History of modern philosophy




History of modern philosophy


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Introduction: Roots of Modern Philosophy

1.Philosophers of the 13th and 14th centuries
2. The Humanism (14th C.) and Renaissance (16th c.) 
3. The Scientific Revolution 
Rationalism and Empiricism
1. General Characteristics of Rationalism and Empiricism
2. Erudite Libertinism and Scepticism
3. Francis Bacon (1561-1626)
4. R. Descartes (1596-1650)
5. Thomas Hobbes (1588-1679) 
6. Pascal (1623-1662)                                                                                                                       
7. Nicholas Malebranche (1638-1715)                                                                                           
8. Spinoza (1632-1677)                                                                                                                      
9. John Locke (1632-1704)                                                                                                                
10. Gottfried Wilhelm Leibniz (1646-1716)                                                                                    
12. George Berkeley (1685-1753)                                                                                                    
13. David Hume (1711-1776)                                                                                                             
14. J.J. Rousseau                                                                                                                            
15. Immanuel Kant (1724-1804)                                                                                                       


Introduction: Roots of Modern Philosophy


1.Philosophers of the 13th and 14th centuries

1. 2 main schools:


Heretical movements of the time demanded answers-responses-defenses from these schools. The task was to study and use dialogue to help them, not behead them. Christianity at that time was studied in depth by philosophy and theology. However, there were no “resources” as we know them today. Rather, people were the instruments, and dialogue was critical for study.

Differences between Dominicans and Franciscans:
Tension between extreme poverty of life and the resources necessary for study and teaching. The most important, fundamental theme is the love of God. We study and preach to understand God, and preaching follows love. This theme (love of God) was emphasized by Saint Francis and became the great theme of Franciscan teachers. They fought against exaggerated reason, even rebelled against reason, because the answer “the love of God” was the best aid for the most important questions.

Pushed for the academic growth in Europe more than anyone or anything else. They placed much more emphasis on reason—it is the point of departure for the renewal of the presentation of the Christian message and the confrontation and resolution of doctrinal problems. The methodology of the Dominicans, especially of Saint Thomas Aquinas, was the use of a great variety of sources to find reasonable and thorough answers. (In other words, Christians are not the only ones who have asked difficult questions…what do the Greeks have to say?  And the Romans?)  It was a very systematic search for comprehensive answers to ancient but real questions.

In summary:
Franciscansàpoint of departure is love of God and, consequently, “moral questions”
Dominicansàapproach problems with debate, dialogue, and reason

The second generation of Franciscan teachers and thinkers, especially Duns Scotus and Ockham, took to volontarianism. They taught that creation came from the love and the will of God, and that human reason is too poor to attempt to understand God. (This had a great influence in later philosophy.)  In regard to the split between faith and reason, Christians should obey, learn the Catechism, but there can be no rational development of faith.


2. John Duns Scotus (1266-1308)

            -after Saint Bonaventure, who was called the “second founder of the Franciscans”
-schooled in Paris, and taught at Cambridge, Oxford, Paris, and Cologne
A large problem for Scotus was how to explain the harmonization of philosophical-rational knowledge and revealed knowledge. He believed that our poor reason is nothing before revelation. Human reason cannot and should not go beyond that which is known by revelation—you cannot rationalize a mystery. He departed from and even condemned Aquinas’ stance of a greater correspondence between faith and reason. Instead, reason should only have practical ends. In trying to protect faith against the reduction of the Christian message to a mere idea in our minds (too much or too strong of an emphasis on reason) he impoverished both. Scotus also avoided a metaphysical theology, asserting that applying reason to a mystery is curiosity—revelation was given that we might know how to be good Christians, not answer metaphysical questions.

Scotus’ difficulty really began with the univocity of being (univocità dell’ente), or the rejection of the analogy of being and metaphysical distinctions. He did not believe that “essence” and “act of being” are different.

àSt. Thomas Aquinas: essence is the “whatness” of something, its definition. Its “act of being” is what it actually is, what is before me. They relate in all created being like act (act of being) and potency (essence).
àAvicenna (and neo-Platonists): “act of being” is just one more step, one more addition that is added to the essence and does not change the being. Essence itself is only a list of descriptions and characteristics abstracted from a type of being. Act of being and essence relate more like substance (essence) and accident (act of being).
In reality, the “act of being” is not just one more step or characteristic of an essence. Rather, metaphysics must begin with real, concrete beings that exist in reality. (A unicorn is not as real as the cat in front of me!)  Scotus would say instead that all beings are the same—the unicorn and the cat are equal, the only difference is that the cat in fact exists and the unicorn does not. In addition, “essence” is not only a list of the characteristics of something. Rather, essence expresses what something is; it answers the question, “What is it?”
Another important thing to remember is that “being” is not just a logical concept. “Being” is not a genre. If it were, it would have to be totally empty and void. Why?  Because all of reality participates in, or can be called in some way, “being.”  According to the laws of logic, the more universal a concept is, the fewer characteristics it has. Now, if a concept is maximally universal (it can be predicated of all of reality), it must also be maximally indeterminate, or empty. But “being” is only that which is, and “being” is never undetermined!  Thus, “being” is neither a genre nor a logical concept.

For Duns Scotus, the essence of something is, then haecceitas, or “this-ness” is the principal of individuation. It is the real existence added to an abstract concept. The passage from the univeral concept of DOG to MY DOG ‘REX’ is because of haecceitas. In reality (according to St. Thomas), primary matter is the principle of individuation—this does not mean that primary matter is the cause of individuation, just the principle—but Scotus feared putting too much emphasis on the material principle of things, and so he invented haecceitas, a formal principal of individuation. Haecceitas is Scotus’ attempt to explain the existence of concrete things without speaking about matter. For Scotus, the name or form of something is the “thisness” of the thing, and it individuates the essence. It is like a “final form” that is added to the essence to make the individual thing. Another name for haecceitas is entitas individuale.
àIn the case of the human soul, the form of the human person, the form comes directly from God. For Scotus, God became the direct cause of all reality.

            According to Scotus, the intellect and the will are separated in God. The human intellect cannot understand divine actions, and we must be satisfied with the explanation that they are the will of God.


3. Wilhelm of Ockham (1290-1347)

            Francisan; he lived at a time when the Franciscans were having political and disciplinary turmoil. He himself led a troubled life, particularly toward the end of it. Where Scotus divided the intellect and the will of God, Ockham divided the will of God from God’s goodness. Therefore, something is good (like the 10 commandments) because God said so, not because the actions specified in the commandments are good in themselves.
The methodological point of view of Ockham’s philosophy is important to understand his teachings. He believed that a ‘system’ of thought should be as simple as possible. That is, our explanation of reality (and how we know reality) must be free from pretention and calculation: entia multiplicanda non sunt praeter necessitate. This sentence is known as Ockham’s razor: being is not multiplied beyond necessity.
The main question for Ockham: What is the relationship between knowledge, language, and reality?
Realistically speaking, language allows us to refer to things that may or may not exist, to speak of the future, to propose theories—it is very useful!  Language moves from our mind to reality and vice versa, especially using universals. Although there may be different levels of abstraction between a concept we know and the reality it refers to, through concepts we know reality.
According to Ockham (not multiplying being more than that which is necessary), language is only a human convenience. Universals are just useful, mental constructions that do not really exist (flatus vocis=empty words). They are a non-reality that actually reduce reality to fit our structures. Universal experience allows for language. Words (suppositiones) are only things that “stand for other things” and “tend toward individuals” (intentiones)—but have nothing to do with the reality of the thing they represent. They do not refer to the essence or a univeral concept, as the Scholastics taught. Language is completely one sided or uni-directional—nominalism.
Ockham also continually separated faith and reason. He believed it was almost blasphemy to try to understand God’s ways. For example, the absurd stories in the Bible are that way because God willed them to be so. We cannot understand God’s will—volontarianism.
He also impoverished metaphysics and the human process of knowing. Ockham believed that knowledge departs from intuitiones—the knowledge process of Saint Thomas Aquinas has too many steps!  Instead, knowledge is like seeing: we are “hit” with information and immediately know; we intuit reality. This way of simplifying knowledge—in accordance with the “razor”—brings with it the consequence of not distinguishing the “hits” or intuitions from the concepts in our minds. We can never be sure of what we really know: our perceptions or external reality?  Our ideas of reality become the reality, they are “opaque”: intentionality is completely lost with Ockham. Later, Descartes will have a similar problem with his own explanation of ideas.
These “intuitions” are separate, and this gives rise to another difficultly. How does one explain cause and effect relationships?  How do we know that fire makes something burn, or that heat causes ice to melt?  These are not intuitable ideas. Ockham would answer that these causes do not really exist, but are rather a name that we give to something we know. The only causes that really exist, according to him, are those efficient causes that we can see. This is a grave problem. For example, the proofs for God according to Saint Thomas depend on causality—there must be a final cause. Also, freedom is not demonstratable or observable; does that mean that freedom and liberty are not real?  Ockham believed that God exists, but that we only know that because of revelation and faith, because we cannot intuit God. There is no metaphysics in his system. Faith supplies what we lack, but if faith is lost…


4. Meister Eckhart (1260-1327)

            German Dominican; he was a “speculative mystic” but not a saint. Some of his works are questionable, especially writings about the eternity of the world and some of his beliefs on the human person.
German speculative mysticism was greatly influenced by neo-Platonist writings, particularly Pseudo-Dionysius and Proclus. Mystical philosophy (AKA speculative mysticism) teaches that God is beyond all conceptual possibilities and that our knowledge cannot explain his profundity. It uses the method of negative philosophy, i.e., we can only say what God is not. We must deny all that we know, because it is a limit that we put on God. Philosophical speculation stops at comtemplation of God.
Creation is “derivation” from the One—“derivation” means the same as emanation from the neo-Platonic One, but was used so Eckhart would not be condemned.  All beings participate in the One. Unity, or the One, is a metaphysical demand or need, and the One is Life. Therefore it is a dynamic: One/Life. In God, who is One/Life, knowing and being are also the same. How is multiplicity explained?  “In the beginning was the Word” (Verbum), not being (Ens), and the Word is truth (Ego sum veritas). Therefore, truth preceeds being, but God is the pureness of Being; He is uncontaminated simplicity. From the One/Life/Purity of Being, one can say that God is being in the sense that He is the cause of all things, but He is also beyond all things. This leads very easily to pantheism—all things are God.
In order to defend the omnipotence of God, Eckhart went to the opposite extreme. There is  too great of a gap between God and creatures, without a plausible explanation of creation.
By way of reason, man can reach God. This does not mean reasoning, but rather that the intellect, through contemplation, must be submerged and transformed in God. This does not mean that man becomes God, but Eckhart’s metaphysical language was not precise enough. It means man is “taken” by God through contemplation, and transformed.

It would be good to mention here the importance of Neo-Platonsim to Christian writers. It obviously had a profound influence on Meister Eckhart, but it affected later philosophers (not always Christian) as well.
For Neo-Platonists (for example, Proclus and Plotinus) the ONE is the most important idea. ONE and UNITY are used interchangeably. Even more than BEING, the idea of the ONE is fundamental for their metaphysics. The ONE, which is purest simplicity, diffuses itself like a gradation of light, called emanation, and thus there is multiplicity. There is a certain metaphysical charm about this theory, especially for a Christian. The notion that all things flow from God in a beautiful and awe-inspiring torrent of “being” has aesthetic appeal. For this reason, Plato (and neo-Platonists) were seen as more Christian than Aristotle, and their theories were embraced. For neo-Platonist Christians, the ONE is God, Who is also a Trinity. BEING is still after the ONE, because God must be beyond being, as being implies imperfection. Then comes the emanation/gradation/derivation which is creation, and there is multiplicity. These gradations want to return to the ONE, and eventually all things will in fact be recapitulated in the ONE. This is not enough, however, to explain the existence of the world. Creation cannot be explained simply as diffusion or gradation, or else there is the risk of pantheism. Also, the recapitulation of all things into God would require that individual identity be lost, or swallowed up like water back into the sea. Revelation and creation (and good metaphysics) tell us that this cannot be true.


5. Nicholas of Cusa (1401-1464)

Harmony and coincidentia oppositorum.
Nicholas of Cusa, like Eckhart, was greatly influenced by neo-Platonists. He solved the problem of One and multiplicity with Harmony. All the order and disorder of the world—the symphony of life—is reworked into a higher order, which is Harmony in God. Because God harmonizes all difference, all complexities, opposites, distinctions, etc. are reduced and brought together. All things will be ordered; even political and ecclesial distinctions will be gone (the Pope was at Avignon at this time).

De docta ignorantia
            Nicholas of Cusa used the negative path of knowledge of God. We can come close, but we will never reach divine knowledge or perfection. He compared God’s knowledge to a circle and men’s knowledge to a polygon within the circle. The polygon can have more and more sides to become like the circle, but it is always infinitely distant from the circle. Where the polygon and the circle touch is a point of wisdom or identity.

God, the world, and man
God is One or Unity, and he creates the world—it is a theophany, a demonstration of God, though not in his totality. Creation is an exit from the One, and is called omnia complicans (all is in God, literally: all things folding up) and omnia explicans (God is in all, literally: all things spreading out). Creation will return to God. Man is like a little world (microcosm) in which all coincides, but he is part of the greater world. All things contain a reflection of God, but this is more priviliged in man. He is a point of synthesis.


2. The Humanism (14th C.) and Renaissance (16th c.)

1. Introduction


            There is much propaganda about this time period. The “heroes” were those who made themselves the most independent from the Church’s “monopoly” of thought and education. In reality, however, there was great continuity with ideas of previous times, and most of the authors were Christian. The ideas were not completely new, but were part of a long and rich development.
In the beginning of the 13th century, many ancient texts were rediscovered and dispersed, usually from the Christian East and Constantinople/Istanbul to the West. Oftentimes the purpose of these exchanges was to confront Islam and defend Christian doctrine. Later, especially in the 15th and 16th centuries, the texts were acquired by affluent Italian families (Medici family in Florence, for example) who opened their own schools and academies. They would translate the texts into Latin directly from Greek, without the Arab interpretation of Aristotle and Plato. Ancient Latin texts were also found, such as Cicero and Seneca; the literary style was greatly admired, and the traditions and mythology found therein fascinated the people. The writings were accepted by many philosophers and theologians as quasi-“revelation.”  Thus, the new translations brought fruit of every type. The great demand for manuscripts led to the falsification of some and a lack of criticism that would have discovered the fake writings. Many works were mistaken as authoritative, historical writings which were in fact fabricated.
The best example of Humanistic literature is the Divine Comedy of Dante. It represents the great fusion of human wisdom (represented by Virgil) and Christian wisdom. Note that Dante places Aristotle in the first circle of hell, which is actually a compliment. Petrarch and Bocacchio are also important. Man (anthropology) becomes the focal point.
The Renaissance (awakening, rebirth) was a sort second development of Humanism, with a particular emphasis on art and scientific technology. It was a religious, political, and cultural revolution which (obviously) had a great influence on philosophy and theology. Only later, in the 1800s, was the name “Renaissance” given to this time period. This was done to emphasize the “awakening” of Europe, the casting off of medieval religious fetters, the re-birth of the human sciences, etc. The truth is that the Church played a great role in the Renaissance, especially in the artistic movements of the times (Michaelangelo, Bernini, Raphael, etc.)

In summary: great exchange of information between East-West, particular emphasis on value of pagan authors (quasi-Christian mentalities in non-Christian writers), a large amount of false information was acquired, and a lack of criticism (historical, literary, etc.) leads to increased relativistic mentality, particularly in philosophy and theology.

2. Marsilio Ficino (1433-1499)

            Linked to Academy of Cosimo de’Medici, and translated many works of Plato and neo-Platonists into Italian. He tried to organize and combine the different texts, to harmonize these new “revelations” with the Christian revelation. In other words, the works of the ancient philosophers were seen as being equal to (or at least almost equal to) Revelation. Ficino called all the works or “traditions” taken as a whole priscateologia. The rational interpretation of the texts, including the harmonization of neo-Platonic and Christian thought, is called pia filosofia.


God and the world/grades of being
Ficino had a hierarchical idea of being; there are five grades or levels:
Human soul
There is a difference between qualities and bodies so that a distinction between form and matter can be made—qualities are forms or determinations of bodies. God is eternal, and diffuses his “light” toward the bottom as charity, beauty, etc. It is less intense as it climbs down the ladder, but creation is still good because it is from God. The human soul is the point of union of all reality; it has the task of putting order to the chaos of the lower levels (matter and forms) and knows things above and below it on the scale of being. The soul is created directly by God.
This system brings with it the usual problem of unity (AKA God) manifested in some way as multiplicity, without really explaining creation or the distinction between God and creatures. One major problem in Ficino’s system is that any soul can bring sense and order to creation. In other words, the redemption wrought by Christ becomes irrelevant, because anyone can do it.
However, there is another theme intermingled in Ficino’s thought that is very important: ecclecticism. While his philosophy certainly lends itself very easily to pantheism, the fact that he incorporated so many different revelations and traditions to make one “beautiful” system was seen as a very positive thing. More traditions (or sources) are good; more dogma, which excludes and stifles some fonts of knowledge, is bad.


Astrology and magic
Through the influence of the new “revelations” of translated texts, Ficino included in his philosophy the idea of universal animation. Astrology “explained” the influence of the stars and other celestial bodies on earth, or the apparent animation, life, and operation of inanimate objects. Later, the idea of the animus mundi was developed. For example, active volcanoes are evidence of the world’s life-force. Superstition and magic are made the foundations for science.
This creates another problem with Christianity, as the miracles recounted in the Bible can be accounted for by the effects of living Nature. The influence of grace on men’s lives cannot be compared to the the influence of the stars, but with philosophies and theologies developed in systems such as Ficino’s, they are viewed as equal players.


3. John Pico of Mirandola (1463-1494)

            He died very young under strange circumstances. He specialized in Greek translations and studied Aristotle according to Averroes; he attempted to reconcile philosophy and theology (like Ficino) and sought a language to incorporate all knowledge. He used the Kaballah to interpret Scripture, i.e., a tradition of Jewish origin of the literal interpretation of the Bible through numbers and quantities signified by letters and words.

God, man, and the system of reality
As a neo-Platonic Christian, Pico believed that, above all, God is One. Before God’s being, one must speak of the simplictiy and perfection of God as One. It is superior to all other attributes. God himself is superior to being, because the imperfect creation has being; thus, God (One) is superior to being. After the One come all other beings—celestial and terrestrial, and these substances each have a soul and independent life.  For example, a tsunami is not just a natural occurence, but has a soul and lives. All this multiplicity must return to the One. How?  Through the work of man by love. As in intellectual substance, man is the place of reunion between matter and God. Pico emphasized human freedom and liberty, and because of this, his dignity. He was opposed to the belief of the power of astrology and magic over the life of man.


3. The Scientific Revolution


1. Nicholas Copernicus ( 1473-1543)

Copernicus proposed a heliocentric planetary system. In other words, he said that the earth is not the center of the universe. Up to this point, it was believed that the earth was the center of the universe, which was consistent with the view that man was the pinnacle of creation, which was subordinated to him. Copernicus’ proposal was revolutionary and difficult to accept, considering the strength of the Ptolemaic and Aristotelian tradition, and the new view of man a heliocentric system seemed to imply.
Copernicus maintained that the earth is a sphere (not flat), which both rotates in place and moves in a uniform, continuous and circular way, as all celestial bodies do. He, however, continued to believe in Aristotle’s spherical system (negated by Tycho Brahe, 1546-1601)


2. Johannes Kepler (1571-1630)

Kepler added to the rapidly changing view of the universe that celestial bodies move in elliptical orbits, not circular ones. He mathematically demonstrated elliptical orbits, which gave a strong push toward the view of the world as mathematically organized by God.


3. Galileo Galilei(1564-1642)

Galileo believed that Copernicus and those who came after him held realistic views of the universe. He trusted the use of instruments of observation (like his telescope), even when they contradicted tradition—putting him at odds with certain Roman professors.
He was called to proceedings to review his “new” ideas in 1616. He was told not to teach or publish these ideas without full demonstration. After the election of his friend Pope Urban VIII (Barberini), however, he published a dialogue about the two systems of the world which rather harshly mocked the traditional view of the universe (remember the printing press was more than 100 years old by now).
Galileo was called to a second set of proceedings for violating the decision of the first process without having found demonstrations for his arguments. He was put under “house arrest” at his villa in Tuscany, where he lived the most scientifically productive period of his life until his death.
It is worth noting that, despite his temperament and imprudent decisions, Galileo was right in a number of his observations, one of which was that the Bible was not made to explain how the universe is structured or the value of empirical knowledge.


The Senses
According to the classical Aristotelian model, the five senses are primary in acquiring knowledge of reality. Aristotle believed the five senses never erred when perceiving their proper objects. He arranged the primary qualities that are properly perceived by the five senses in the order that follows:

  • Sight perceives color
  • Hearing perceives sounds
  • Smelling perceives odors
  • Taste perceives flavours
  • Touch (a little less articulated) perceives a number of realities like temperature, roughness etc.

According to this hierarchy, sight is the highest sense because it relies least on material and allows us to identify and distinguish. Hearing allows us to reason and speak and is tied closely to language, so it comes second. Touch is the lowest of the senses, relying most on material—but it is the most indispensable sense.
The objects of the common senses were secondary qualities to Aristotle. He considered the knowledge we acquire using a combination of our senses to be less reliable. For example:

  • Movement (velocity) can be perceived with sight, sound, touch and perhaps even smell
  • Number (quantity) can be perceived with sight, touch

But, sights, sounds, tastes, smells and sensations aren’t quantifiable—they cannot be converted into numeric quantities in the same way the objects of the common senses can be. Aristotle’s primary qualities rely on the subject who perceives them to a certain degree. You can’t apply a mathematical equation to sight, but you can calculate velocity (V=distance * time).
Galileo wanted to universalize observations and move beyond spontaneous-type knowing of the physical world. For him the common senses were much more useful for scientific and universal equations. For this reason, in keeping with the momentum of scientific progress, Locke switched the primary senses to second place, all but disregarding them.  Sights, sounds, tastes etc. became secondary qualities, considered too subjective and imprecise. Those objects of the common senses he called primary qualities, because they are quantifiable and more precise.
Locke was right regarding technical knowing, but spontaneous observation, which is helpful in philosophy, was lost. By disregarding the qualities properly perceived by our five basic senses, one admits only quantifiable knowledge. It limits reality to what is mathematically precise. This time period saw philosophers who aimed to found their philosophies on the precision of the common senses. In other words, empirical data is all that counts.


4. Isaac Newton (1642-1727)

Newton was a great scientist and a man of faith. His ideas would provide the guidelines for philosophers and scientists for two centuries.
By Newton’s time, scientific developments were already greatly influencing philosophical thought (Descartes). The Aristotelian/classical view of the universe (earth as the center of the universe, celestial spheres, circular orbits) was outdated.
Newton’s great discovery was that the orbits of celestial bodies/planets is elliptical and determined by gravity. He mathematically calculated that orbits depend on the masses of the objects in motion. The earth stays in its orbit by the gravitational pull of the sun, and the moon does likewise in relation to the earth. Newton’s find opened the way to a view of the universe that could be reduced to geometry.
Newton took his discoveries and explained them in a comprehensive way. He proposed how to do philosophy with simple methods and few rules. It is noteworthy that at this time, science as it is thought of today and philosophy were not clearly distinguished at this time. In this way, he reduced many observations and traditions.
Newton’s philosophical and theological writings were far more prolific than his scientific writings, but he was the envy of all other philosophers for his calculations. He proposed four rules as a methodological approach to philosophy of nature.

1. Do not explain natural things with more causes than those which are true and sufficient to explain their appearance.

2. For natural effects, search natural causes.

3. Qualities which do not augment or diminish in degree and that are found in all the bodies within the realm of your experiment must be considered universal qualities. (Think of the previous paragraph on primary and secondary qualities. Qualities that are reducible to numbers are useful for philosophy of nature.)

4. In experimental philosophy, conclusions inferred from phenomena by general induction must be considered true or very close to the truth unless other more exact conclusions are found. In other words, if you come up with the same results over and over, trust them until or unless a more exact experiment surpasses them.

While Newton discovered the existence of gravity, he admitted that he could not explain its nature or the reason for its existence. He acknowledged the limits of natural philosophy. Hypotheses non fingo. He said that the machine of the world must come from an Intelligent Being.


Rationalism and Empiricism


1. General Characteristics of Rationalism and Empiricism

One classical didactical approach to modern philosophy begins with Descartes (rationalism) and Francis Bacon (empiricism), and compares the two separate philosophical lines of thought until Kant. Instead, the following will provide the general characteristics of both rationalism and empiricism in regard to fundamental philosophical questions.   

  • Renewal. Both rationalism and empiricism had the general thrust to “throw out” what they viewed as old and to start over. They sought to provide a new metaphysical foundation to philosophy and to find a new method to do philosophy. Usually, this metaphysical foundation was very different than a Thomistic or Aristotelian model.


  • Knowledge/Knowing. The problem of how we know came to “center stage” with modern philosophy. Philosophers found it fundamental to construct a theory of knowledge before proceeding to different fields of science. Their rationale was: if our mind is the instrument of philosophy, let’s find out how our “instrument” works.
  • Secularization. Modern philosophers moved away from the university system and the Church. They sought to eliminate recourse to God’s providence in their explanations. Philosophers were not necessarily believers anymore. Also, the printing press made information more available to a broader audience. Protestantism brought other church-affiliated universities as alternatives to the Catholic Church, intellectual life, Latin, and university faculties.


  • Domination of Nature. Nature was no longer looked at as something to be contemplated, but as something to be used and mastered.
  • Subjectivity/Subjectivism. The subject and not the object, became the focus of philosophical thought, which seems to hold a certain contradiction. On the one hand, classical philosophy was rejected as too subjective in its dependence on the five senses and what were by then considered secondary qualities. On the other hand, speaking of the subject (man) and his way of knowing became primary, while reality (objects) was no longer considered (idealism).


  • Faith in Progress. This time period saw an attitude toward progress as a good in itself. The past was mistrusted and disregarded as static. This brought prejudices against religion with it. Philosophers tended to have fixed sentiments against traditions (scientific, philosophical, the Church).
  • Relation between body and soul. With a disregard and distrust of classical philosophy, rationalism and empiricism no longer considered Aristotle. They looked at the notions of potency and act as outdated, leaving the way the body and soul relate an unsolved (or poorly solved) question.


2. Erudite Libertinism and Scepticism

The origins of libertinism and scepticism stem from Italian humanism and the Italian renaissance. Recall that classical Greek literature came to Italy in the fourteenth and fifteenth centuries, bringing with it a certain scepticism. There was a tendency to put pagan literature on par with Christian literature. From Italy, these ideas spread to France, and France became the cultural point of reference in the fifteenth century.
France saw a great exchange of information among peoples and cultures from all over Europe and was enjoying wealth—which made time, literature, and suitable places for discussion available. At the same time, religious violence among Catholics and Protestants was prevalent, making “strong” or “dogmatic” positions unattractive.
The “intellectual fashion” became vast knowledge of cultures and customs of different peoples. They “toyed” with various notions about morality, the origins of society, and the idea of the “good savage” without the interference of culture and religion.
In general, libertines and sceptics tended to lack academic rigor or discipline and they opposed university rules. To them, anything that resembled a dogmatic decision was to be avoided.  Their philosophical “study”  was done in the salon or the lounge. They rejected the classical view of knowledge—they didn’t care to distinguish memory and the intellect. Religion in these circles was seen to maintain social conditions, and morals were viewed as adaptable to circumstances, even if certain general principles could be admittedly useful cross-culturally. Libertines and sceptics emphasized refined, elegant behaviour for men (as opposed to the type of dogmatism they believed leads to burnings in Campo de’ Fiori).


Montaigne (1533-1592)
Montaigne was one of the sceptics as described above. He maintained that everything changes and nothing is as men thought it to be. As science turned human knowledge of the universe “on its head,” so it is with men too.
Montaigne posed the question whether or not faith was better than atheism. His answer does not consider truth, evidence or revelation. Faith to him was better, but only for its usefulness in society and comportment. Rational thought was not properly applied to God or religion. There was no possibility of discussion between faith and reason
For Montaigne, philosophy was wisdom. It was a style of life, a way to live happily amidst constant change. He proposed that one choose what is good and useful in the present. His view of the “gallant man” was one who knew pleasures, poetry, and music, but Christian asceticism was implicitly rejected. He rejected the world as black and white, good or bad.

Pierre Bayle (1647-1706)
Bayle lived in a century of religious wars when Europe was divided according to religion. His main work, Thoughts on the Comet, was a reaction to a comet predicted to hit earth, that never did. In it, he criticized all explanations of nature that are not reduced to facts. He felt superstitions and religion coincided  and that preachers used false ideas of Providence to manipulate people’s ignorance. He criticized institutions, especially the Church. He was a forerunner of Voltaire and Hume in his manner of criticizing religion.


3. Francis Bacon (1561-1626)

Francis Bacon’s mother was a Calvisnist and his father was high-up in the court of England. He studied philosophy at Cambridge and jurisprudence in London. He wrote many works, most importantly, Novum Organon, in which he sought not to renew, but to re-found science (like Bramante destroyed St. Peter’s). He said the greatest three inventions were the compass, gun powder, and the printing press.
To Bacon wisdom and knowledge serve men to gain dominion over nature, logic being the instrument of gaining knowledge so that men can come to a better life. Knowing was useful. Contemplation or knowledge for its own sake was a waste. Bacon’s idea of empirical science was mechanicism
Bacon criticized magic, philosophy and prejudices. He disliked magicians because they confused the profane with the sacred. To him, their products were mere chance because they used no logical method.
Aristotle’s style of thought and discussion was useless in Bacon’s eyes. He saw talk of virtue as obscure and he despised Aristotle because he discussed empty, abstract things. Aristotle was mistaken because he trusted discourse instead of  experience. Bacon, in turn, reduced Plato to mostly a political thinker. He saw Plato’s approach to nature as sterile and his theology as noxious like Aristotle’s dialectic.
To arrive at more useful knowledge, Bacon indicated four idols/prejudices that needed to be destroyed:
1. Idol tribus (tribe). This includes all the prejudices that span the human race. He wanted to refute the tendency men have in their weakness to accept and maintain general opinions.

2. Idol specus (cave). This idol is the attachment, defense and universalization of one’s own discoveries.

3. Idol fori (market). The types of errors that arise from contacts among men in environments like commerce breed this idol to Bacon.

4. Idol theatre. Faith in previous philosophies produce this last idol. Instead, Bacon felt that earlier philosophies should be considered like fables represented on the stage.

Finally, while not negating that final causes may exist, Bacon felt they were outside the scope of his method.       


4. R. Descartes (1596-1650)

Descartes was a Catholic, though he travelled with a Protestant troupe. He attended the school of the Fleche, run by Jesuits, where he was presented with the rationalistic view of scholasticism/Thomism as summarized by Suarez. The Thomism Descartes learned was a reduction from its original fullness. His education was not limited to the university setting. He travelled, exchanged ideas in Paris etc. Descartes died of the flu in Sweden after coming to court at the request of Christina of Sweden.

The ideas of Truth, Evidence and Certainty:
Being unsatisfied with the metaphysics he learned, and wanting to oppose the sceptics of his time, Descartes sought a foundation and method of philosophy that was clear and certain like math (he is also noted for his contributions to geometry). At the same time, Descartes did not put stock in what we can know through experience.
Descartes felt he found the solution to his problem in methodical doubt. To him this meant he had to start from what is evident and certainnot truth that must be demonstrated—which is easy to criticize.
What does it really mean when something is evident, certain, or true?

1. What is evident is immediately present to the subject (or in a mediated way—like knowing the movement of celestial bodies by way of mathematical equations). It is important to note that it is within a subject that something is evident.

2. Truth is adequatio intellectus ad rem. Truth does not rely on the subject who perceives it, but is ontologically/transcendently real. Truth depends on being. Something is true in the intellect when the intellect accurately perceives what is in reality.

3. Certainty is a state of security within a subject. It does not necessarily relate to being outside the subject, but it means that the subject is convinced.

This means that evidence and certainty are subjective—depending on the subject who perceives them, while truth is objective—depending on the object perceived. For example, a person (subject) can feel certain that the sun revolves around the earth based on the evidence his sight immediately provides, but his certainty does not correspond with the truth.

Descartes developed the following method to do philosophy:

1. Evidence. Do not take anything as true unless it appears clearly and distinctly so that the intelligence can rule out all doubt. Knowledge from our senses and experience does not qualify as clear and distinct. It is doubtable. Instead, look for what is so evident that it is almost intuitive—something that no one could object to, and start from there:  COGITO ERGO SUM. “I think, therefore I am” was Descartes’ evident foundation for his philosophy.

2. Analysis. Look at every aspect of a question, seeing every possible angle, break down the problem into as many parts as possible. (Recall that the whole is more than the sum of its parts—ex: a person is much more than his parts considered separately)

3. Synthesis. Put together all of the elements to come up with a vision of the whole—it should be mathematical. Order all of the thoughts produced in the previous step little by little, reaching a more complex knowledge. Recompose from the simple.

4. Enumeration. This means making revisions in order to be sure you haven’t missed anything

The point of this method is to arrive at ideas which are clear and distinct. It is a reductive way to do metaphysics. Reality and being are much more complex and less mathematical then this method admits.

Descartes on Ideas
It is important to note that Descartes’ notion of idea is often ambiguous or contradictory. It focuses almost entirely on the subjective aspect of knowing as opposed to objective reality. He distinguished three types of ideas.

1. Innate ideas. Descartes mistrusted our five primary senses (which he would have called secondary). To him, if we want scientific certainty and evidence, our senses are not the proper source. And yet, we have some perfect ideas in our mind—the idea of God as perfect and eternal, etc. If our external senses are so imperfect, from where could these perfect ideas have come?  The only answer is that this perfect Being must have given us these ideas of perfection. God presents himself to the intellect as the innate idea of a being that is causa sui—that is cause of himself, causa sine ratio—a cause without reason. (This not only explains the origin of some of our ideas, it is a demonstration of God that relies entirely on the subject. God viewed as a cause, makes His effects necessary, not freely willed. Pascal criticized this “use” of God to resolve philosophical problems).


2. Temporary or Casual Ideas. Descartes’ second classification of ideas came from his work in anatomy. While studying the eye of a bull, he noted that it reflected images up-side-down. He concluded that when we see, we receive sensible impressions that leave images, which we “store” in our minds as ideas. These images seem like tiny negatives, representations, or copies of reality. In other words, we know these mini “slides,” when we know, and not the reality itself. Descartes left out an explanation of the internal senses or any way to explain the immateriality of ideas. It leaves us with a kind of intuitive knowledge.

3. Made or Constructed Ideas. These ideas are constructed by the subject

Descartes on Substances: 
Recall that Aristotle distinguished substances and accidents. To him, substances are those beings which exists in themselves, and accidents are those beings which exist in another. Instead, Descartes  defined substance as “the thing which exists in such a way that it does not need any other to exist.”  What does Descartes’ definition of substance imply?  To what thing(s) can Descartes’ definition actually apply?  Really, the only Being which needs no other to exist is God, which would make all other reality an accident of God. To Descartes, reality is only two substances: res extensea and res cogitans. To him all matter is merely extension. He reduced all material things to parts and their movements (mechanicism). Whereas the Aristotelian concept of matter distinguishes matter from its first accident, which is quantity or extension, Descartes identified matter with its first accident. The other substance, RES COGITANS, has the essence or nature to think. Descartes recognized that all material and spiritual substances are imperfect in light of his definition of substance.
Spinoza agreed with Descartes’ definition of substance and took it to its logical conclusion, making accidents of God (which he called attributes), res cogitans and res extensa.


The body/soul problem
Descartes believed that men are made of his two substances, thought and extension (quantity). He saw the intellect as a thinking substance whose whole nature it is to think—res cogitans. He considered matter to be the same in all the universe, having as its nature extension—res extensa. The human person consists of these two substances. According to his definition of substance, however, these two substances are completely without need of any other thing. Then how and why do soul and body relate?  Descartes’ res cogitans and res extensa arrive at a sort of Platonic dualism. Needing to solve this problem, Descartes turned to his contemporaries who had just discovered the pituitary gland. Descartes decided this gland connected body and soul as the “seat” of the soul.

First, the realistic view of how we know (so that mistaken viewpoints can be more easily recognized):

Aristotle and St. Thomas believed that we are not born with innate ideas, but that we grasp concepts using the knowledge that comes to us first through our external senses, then to our internal senses, which our intellect uses.

Knowing is a way of life for those beings with such a capacity. It is an activity. When we know, we receive external, material stimulus through our sense organs, which are inseparably united to corresponding faculties of our soul. But knowing does not remain on the material, physical level, nor is it primarily a passive receptivity. Our faculties actuate the immaterial forms they receive from reality. Then, our internal senses—estimative, memory, imagination—grasp, connect and separate the information from the external senses. At this level, knowing is already immaterial. The forms that come from objects in reality are not retained in a material way, even if these faculties are connected to organs and the initial stimulus is a material one. The faculties of the soul grasp the forms present in reality through our external/internal senses and offer the forms to the intellect. The intellect abstracts universal forms from the internal senses, which we call concepts or ideas. Ideas are entirely immaterial and intentional. In other words, our concepts are not any kind of barrier between our minds and reality itself. They are entirely “transparent”—not transparent in the sense of having a material consistency—but transparent in the sense that they do not block or obstruct the intellect’s access to reality in any way. Ideas or concepts “tend toward” (hence the word ‘intentional’) the reality from which they are grasped. We do not know only our representation of reality, which is what idealism claims. This would leave us locked in our own minds with no chance of really knowing the world around us. Ockham’s theory of knowing as “intuition” and Descartes’ temporary or causal (very material) ideas fall into this type of trap.  They both render our ideas “opaque” as opposed to “transparent.”

Descartes on causality/a mechanical world
Descartes saw the world as merely extension in total continuity, guided by mathematical laws established by the Creator. To him, there is no empty space. The world, for Descartes, is an enormous mechanism made of homogenous elements that are distinguished only by movement. Geometry is capable of explaining all the movements and transformations in matter (res extensa). There is no reason to try to discover any causes aside from efficient causes.

Descartes on morality
Descartes saw knowing like a tree—the fruits of which are morality. His intent was to re-found the entire tree of knowing based on the metaphysical foundation cogito ergo sum, but he never succeeded in completing his system before he died.


5. Thomas Hobbes (1588-1679)

            Interestingly, he specialized in Scripture, especially with Latin and Greek, but he really believed in geometry and its method (progress and mechanicism). He was born a Protestant in England in the year of the defeat of the “invincible” Spanish armada.

Characteristic elements: materialism, empiricism, etc.
Hobbes was an empiricist, like Francis Bacon, and believed that philosophy must be useful. He also believed that all philosophy must begin with the precision of a geometrical method, and anyone who would study philosophy must first study geometry (because all improvements in man’s life come through geometry/science)—otherwise you are wasting your time. The most important elements of his philosophy are materialism and mechanicism. He was totally opposed to the idea of “spirits”—they don’t exist, but are only a manifestation of matter. The “soul” is the name we use to explain certain physical movements. Hobbes does not negate the will or the passions, but gives them mechanical explanations and calls them “particular movements.”  These movements also belong to animals, but human beings are higher on the continuum because we are more sophisticated matter.
Hobbes was a nominalist; he believed that universals do not exist, but rather only individuals. We give a name to a certain concept because it functions as an instrument for reasoning, not because a thing has a certain essence. Naming in a universal way is useful, and nothing else.


Man is not a composite of body and soul, but a chunk of matter, although a rather sophisicated one, at least moreso than animals. The good for man is pleasure, and the bad is pain. All reasoning is calculation. Ideas, or thought, are simply phantasms produced by external stimuli, like smoke that remains after the stimulus is gone. All mental phenomena are like this. Hobbes has no intentionality in his philosophy.
No final cause or ultimate happiness influences our decisions, but only the weighing of advantages against disadvantages. These calculations should not waste any time with abnormalities, but take the mean—whatever a majority of people would do.
Man is egoistic, in that he seeks pleasure and his own advantage. This is not a vice, however; there is no moral dilemma here. Rather, it is the way we are made. Felicity comes from pleasure regulated by calculations. All passions are reduced to animal, tendential movements. The difference between the intellect and the senses is considered according to physical alterations. If a concept acquired by the senses is communicated to the heart, it is a passion.
Hobbes distinguished between conscious activity and unconscious activity in living things through “moti vitali” and “moti animali-volunatari”. The first, vital movements, are those that do not require imaginative activity, such as the heart beating, digestion, etc. The second, animal movements, are those movements like speaking, going, willing. Neither group is specifically a human act, because men are only animals. Our calculations take all these passions and modes of behavior into account, as well as the pleasure/pain of a choice or activity. The freedom or liberty of man is minimalized by Hobbes. It is a) the possiblity to manage the calculations we make—which are preconditioned by emotions and deliberations; b) the last movement of the will before an act. Our only real choice is to act or not act.


Political philosophy
Leviathan is Hobbes’ claim to fame. It is basically a treatise on the individual, society, and the state. The image is a half-man/half-beast monster from the Old Testament book of Job. Hobbes attempts to answer the questions of why society functions the way it does, and how can we improve it.
Departing from man’s naturally egoistic nature, Hobbes claims that the “pure nature” of man is NOT that of a social animal, but rather an isolated one. All men seek the same thing—their own good. In order to survive, they have to work together, cooperate, but this is only done out of self-interest. Once a community is large enough, one man or a group of men must be put in charge in order the govern the interests of all. This person is called the “state” and must be like an ultimate judge. He is chosen by mutual agreement among the egoistical men, who accept certain disadvantages in order to survive and live well. This is called the “social pact.”  The politician or governing body is a semi-god (Leviathan) and can be a president, parliament, king, etc.
With this social pact, men renounce much of their liberty and judgment for the sake of obedience to the state. The Leviathan is, in a certain sense, outside of or above the society so that it can be neutral. Rebellion is only justifiable in very extreme cases (as one’s first desire is to maintain one’s own life) and it would normally go against the calculations of advantageous action.


6. Pascal (1623-1662)

Pascal grew up in a non-practicing Catholic family. His father educated his children. Pascal showed early signs of genius. He wrote a treatise on cones at the age of fifteen, which was published the following year. Pascal had an initial conversion to Christianity when he became associated with the monastery of Port Royal, where they practiced Jansenism. The heresy included scrupulous morality and a manifestation of election (being among the chosen of God). They based their beliefs on a book called “Augustinus”—written by Jansen. The heresy had a distinctly Calvinist element. Pascal’s sister entered the convent at Port Royal. Still, Pascal focused his energies on geometry and other mathematical/empirical disciplines until a second conversion. At that time, he began to write apologetics against philosophies that he believed would lead to atheism (including Descartes). He distinguished between the God of philosophers (impersonal/ “cold”) and the God of Abraham (a personal God), endeavouring to apply his analytical, prodigious mind to the service of God. He died young in Paris and his writings were published posthumously by his sister. There is speculation that Pascal was reconciled to the Church by a parish priest on his deathbed.


Pascal’s reason of the heart
In response to Descartes’ rationalism, Pascal indicated a higher faculty—that of the heart, which senses God in a way that the intellect alone does not. He described the relationship between body and intellect as habitual. Taking account of the relationship the intellect has with the body, he felt that we need more than demonstration, which few things consent to anyway, to be moved or convinced.
Pascal believed in two different types of knowing that allow two different ways of deepening our knowledge of reality—l’esprit de finesse (the spirit of intuition) and l’esprit de géométrie (the spirit of geometry). Technical principles are proper to the spirit of geometry. They are principles that are outside the realm of common use and difficult to pay attention to because they do not take the whole of human nature (the body/habits) into their kind of knowing. The principles of the spirit of geometry, however, are perfect and so evident you cannot deny them. On the other hand, the principles of the spirit of intuition are “under everyone’s eyes” and part of common use. They aren’t hard to pay attention to, but they require truly good “sight” to grasp them. They are numerous and “whispy”—it is nearly impossible that some do not escape. One needs to see them all with a balanced mind in order not to reason falsely in regard to such principles. It is in these matters that Pascal called Descartes useless and uncertain.
Pascal criticized Descartes for using God as a mere instrument to start his  philosophy (Deus ex machina).

To Pascal, man is evidently made to think. In thought lies man’s dignity and “trade.”  His duty is to think as he should. The order of thought begins with man’s self, his Author, and his end—but so few men do more than think of means to entertain themselves. They want to become “kings without thinking of what a king is or what a man is.”
Man exhibits a tension between his greatness and his misery, his opening to the infinite and his finiteness. Man’s dignity is in his marvellous ability to think, while at the same time he is miserable for the stupidity of his defects. In his writings, Pascal implores men to listen to God and learn from Him.

Pascal’s Wager
Pascal proposed a bet for those sceptics and rationalists who seek only pleasure and diversions, or who search for a rationalized god and don’t find him. At stake in the bet is the true and the good. Only two things are necessary for the bet:  reason and will—knowledge and beatitude (versus error and misery). This is an unavoidable choice. If one evaluates the wager, the possible gains are infinite happiness and eternal life, while the losses could only be finite (because man has only one finite life and has nothing more to put “in play”). If one wins the bet, he gains everything—what is infinite and eternal. If the bet was wrong, man loses nothing. He remains with what was his in the first place (one finite life).


7. Nicholas Malebranche (1638-1715)

            The point of departure for his philosophy is Descartes, especially the separation of res cogitans from res extensa. He “solves” this with occasionalism—the direct intervention of God at every moment of man’s life. **Another philosopher, Arnold Geulinex, compared occasionalism to  two perfectly synchronized clocks. One is the body, the other is the soul; God intervenes constantly to keep them running smoothly. Malebranche is the last important Catholic philosopher, and he believed that reason and faith at least have the same object: truth. He desired to reconcile rationalism with Christianity.

Ideas and sensations
Malebranche followed—to a certain extent—the Augustinian tradition of the Ideas that are in God. Some ideas cannot come from matter because the body is too weak to understand such sublime concepts like God, truth (the “innate” ideas of Descartes). The contemplation of these ideas brings us to God.
Malebranche also distinguished between primary and secondary ideas. Primary ideas are derived from extension and are independent from us. They can be understood numerically as quantities within a body (or qualities that are measurable). These can be “converted” and made more complex through mathematics, as in the case of the sciences. Secondary ideas come from the perceptions of each sense. The idea is the immediate object, most close to our spirit, which is known when we perceive an object. When we know, we know the idea, and not the actual object, because we cannot know anything other than what we perceive something to be.

Spirit                à                    Idea (known)               à           Object (unknown)

            All ideas come from God; we do not create them. God intervenes in every occasion of sensation and knowledge. We know and contemplate these ideas through the direct, continous intervention of God in our lives.
Therefore, the interaction of body and soul, of sensible perception and knowledge, is a direct intervention of God. It is an “occasion” for God, and the perception itself is called an “occasional cause.”  Why would God choose to create this way?  Because he willed it. The use of God by Malebranche as the efficient and final cause eliminates any difficult explanations he may have had to give about his philosophy.
Interestingly, God intervenes in our lives not by grace, but by occasion. There are many unsolved problems with this. If God intervenes directly in our act of knowing, why does not every person understand all things perfectly?

What role does the liberty of man play?  If a person does not get out of bed in the morning, it is not because he is lazy, but because God did not act—it was not an occasion!  Malebranche said that the will in man is the desire for good, which is an action of God. It comes before liberty. Actually doing the good is liberty, and that is the action of man. However, it is without real efficacy. Malebranche is vague on this point.
The principle virtue is the love of order, exercised in submission to divine law. Again, this is obscure, because all actions come from the occasion of divine influence on our lives—how is their evil, sin, etc?


8. Spinoza (1632-1677)

Spinoza was of Jewish, Portuguese origins and was born in Holland. He was educated in the Sacred Scripture, the Talmud, Hebrew, Latin and other languages, mathematics, and medieval Hebrew philosophy. He had contact with the philosophy of Hobbes, Descartes, and Bacon. By the time he was in his early twenties, he was expelled from the synagogue for his unorthodox philosophy. He never accepted any university positions, wanting to remain completely free in thought.

The method of Spinoza
Spinoza believed his philosophy was more than an intellectual project, but rather vital knowledge that would permit eternal enjoyment by way of knowledge of nature—educating the intellect to guide all of the sciences and arrive at the highest human perfection. He looked at religion as that which requires obedience and leads to prayer. Philosophy, instead, leads to truth. Spinoza had a Gnostic sense of rational knowing—a soteriological (saving) philosophy. The intellect develops itself departing from the notion of God, following a deductive method, reaching unity and identity with nature because: ORDO ET CONNEXIO IDEARUM IDEM EST AC ORDO ET CONNEXIO RERUM.

Degrees of Knowledge
-Imagination, from the senses, is useful but confused.
-Reason is idea in itself, without relation to objects.
-Intuitive science departs from the adequate knowledge of the formal essence of certain attributes of God and arrives at the adequate knowledge of the being of things.
-Truth, idea and essence are the same. It is in this that one discovers what God is by way of the human mind.

God or the Substance
To understand Spinoza, one needs to understand his idea of God. God is the one substance that exists. All other things we perceive, including ourselves, are attributes (like accidents) of the one Substance. Spinoza arrived at this intuition of God/Substance because he used Descartes’ definition of substance and brought it to its logical consequences. Descartes called substance that which needs no other thing to exist. In effect, that leaves only God as a true substance, because all other things besides God rely on other things to exist—they are contingent.  Using Descartes as a point of departure, Spinoza redefined substance as that which is in itself and is conceived of per se, that is to say, that which the concept of which needs the concept of no other things to be formed.
God or the one Substance has infinite attributes (accidents) to Spinoza, but we only know two of them—res cogitans and res extensa. Thought and extension are among the infinite attributes of God, but they are the only ones in which we “take part” and know. Because they are attributes of the one Sustance, thought and extension do not relate to each other to form individual substances (like Aristotelian/Thomistic philosophers may think), instead, they run “parallel” to each other, inhering in God among the other attributes.
Then, there are modes of the one Substance. Modes are “affections” of the Substance or those things that are in another thing by which they are also conceived of. Modes can be finite or infinite, properties of the attributes, and also things, effects, in the formal-deductive sense. All is caused and deduced from God who is substance or Nature (or both). This is what Spinoza called panentheism—all is in God (it’s basically pantheism).

Substance/God-Nature presents itself in two situations. The first is as Natura naturante—that which is in itself and conceived of per se. In other words, natura naturante arethe attributes of the Substance that express its infinite and eternal essence, which is God considered as a free cause. Natura naturata is all that follows from the necessity of the Nature of God, all the attributes or modifications of God that without God could not be or conceived of. God is the cause of Himself in the sense that his being converges with his existence.

Man, Soul, Body, Liberty and Passions
The essence of man is constructed of certain modifications of the attributes of the Substance. The soul is the idea of the body and the body is the object of the soul. There is a mutual correspondence or parallelism between body and soul for Spinoza, but they are in no way actually united. They remain entirely separate as two attributes of the Substance. Consciousness is the idea that the soul has of itself. Passions are not then weaknesses in the soul, because soul and body are in no real way connected, but they are manifestations of the power of Nature. The passions tend to persevere in their being, and the mind is simply conscious of their movements. Movements which are totally mental are called will. Movements that are referred also to the body are called appetites. From joy and pain come all other passions, which are deduced to more geometrico.
We think we’re acting freely, but really Nature is moving our passions and we are merely aware of it. Really, we’re ignorant of the causes which determine our actions (but we are certainly not among the causes of our actions). Liberty is then consciousness of the necessary, determined movements we undergo.

Political Philosophy
To Spinoza, political powers rightfully have charge of sacred things, but philosophy requires freedom. A person must act with the state even against his own conscience. Before religions, tolerance is the necessary notion.


9. John Locke (1632-1704)

            John Locke was born in Wrington, England. He was much involved in politics and social life. He is known as a semi-empiricist (for reasons which will be explained later) and for having had a certain amount of common sense. In other words, he respected reality to some degree, even if it rendered his philosophy contradictory or inconsistent at times. He was also much at the mercy of various political obligations and powers, which may have restricted the cohesion of his thought. He had what could be called an eclectic philosophy.

The Essay concerning Human Understanding
Locke can be credited as being the first philosopher to concentrate mainly on human knowledge. His primary work is the Essay concerning Human Understanding. It was born from a philosophical discussion with friends about what men can know and not know. It took years to write and is a compilation of sometimes incoherent or repetitive “parcels” and “catches.” Locke undertook the inquiry because he felt men frequently wasted their energies on problems that the human mind cannot solve. He wanted to establish what falls within the scope of the human intellect in order to make real progress in knowledge. The Essay is organized in four main parts:

  • Polemics against innatism
  • The origin of ideas (simple and complex)
  • The relationship between words and ideas
  • Certainty, extension and degrees of knowledge

The origin of ideas and polemics with innatism
            Locke began his Essay by establishing that our ideas come from experience and are not innate (contrary to Leibniz and Descartes). Against the rationalist argument that some ideas must be innate because they are universal among men, Locke says that even if universal ideas did exist, other explanations of universal agreement are possible, which renders the hypothesis of innate ideas superfluous.  To further refute innate ideas, Locke attempted to demonstrate that not all men share universal ideas, nor do they share moral values. He concluded that experience is the font of all ideas, which is the mark of British empiricism. For empiricists, men are born tabula rasa. This is not to be confused with a Thomistic/Aristotelian theory of knowing. While in moderate realism, it is true that ideas are not innate, knowing is a way of life. It is not passivity but requires the actualization of forms. Further, our ideas are intentional and “transparent.”  They give us an immediate knowledge of reality, whereas with empiricism, ideas provide only mediated knowledge. (See “Knowing” under Descartes for a more detailed treatment).
The reason Locke earns the name semi-empiricist is because he accepted the ideas of God and self to be innate (like Descartes/rationalism). In this way, he incorporated rationalism into his empiricism. Locke recognized that we do not perceive our idea of self through our senses, yet he saw it as the clearest idea we have, so he conceded that we are born with an innate or intuitive idea of self. To be born with this innate idea, God must exist.  These two ideas Locke called “privileged” compared to all other ideas that come from sense experience. Hume strongly criticized this compromise in Locke’s empiricism.

Primary and secondary qualities (mechanicism)
            Locke believed that atoms or tiny particles make up all of reality and that the movements of these particles physically effect our senses. We in turn perceive these particles and their movements as color, sound, smell etc. In other words, colors, sounds, smells and other such qualities do not really exist outside our perceiving them. For this reason, Locke determined that the five senses give us secondary qualities that rely entirely on the subject. The qualities that exist in reality, or the primary qualities, are quantity and movement. Quantity and movement exist independently of us and produce the effect or phenomena of secondary qualities in us.

Qualities and Ideas/The wisdom of the Creator
            Ideas to Locke are those objects which the spirit perceives in itself. They are phenomena in the spirit. They come from our perceptions of the qualities of objects. For example, the qualities of a snowball produce in us the idea of cold, white and round. The problem is that, because we perceive only secondary qualities, we don’t know what the snowball is in itself, we only know what phenomena the movements of its particles produce in us. In this way, the immediacy of human knowledge is lost (thus our ideas are not intentional or “transparent”).
Locke tried to reconcile the gap his distinction of secondary and primary qualities left between our knowledge and reality by recourse to what he called the wisdom of the Creator. When we cut ourselves, we don’t experience the movement of particles (primary qualities), we experience a feeling of pain in our spirit. The feeling of pain is entirely unrelated to the primary qualities of the action itself. Our Creator designed this point of contact between us and reality. Physical movements in reality produce corresponding (but unrelated) simple ideas in us according to God’s design. While our perception of the movements of particles as colors, touches, sounds etc. are entirely subjective and unrelated to the primary qualities, we must trust in the wisdom of God.
The above paragraph describes simple ideas, which come directly from sense perception and are received passively. Locke also admitted that our intellect forms complex ideas that always rely on simple ideas from sense-experience (except the ideas of self and God). He divided complex ideas into three types: relations, modes and substances. From the ways our simple ideas interact arise relations. Our intellect compares our ideas and comes up with cause-effect, identity, and moral relations. Modes are not subsistent in themselves as ideas, but are dependents or “affections” of substances, for example, gratitude or murder.

Locke on substance
            To Locke, our ideas come from our perceptions of qualities as described above. While we cannot see or perceive the substances in which qualities inhere, we can suppose that a substrate exists hypothetically because we are accustomed to thinking in this way. Substance is then the supposed but unknown substrate of the qualities we perceive. 

            Locke saw our language as a convenient way to refer to our ideas that are “general.”  Words to Locke do not refer to real essences but are efficient, useful signs that we invent.  It’s useless even to ask if essences exist since we cannot know them.

Degrees of Knowledge
            We know, to Locke, when the mind certainly perceives and is undoubtedly satisfied with the agreement or disagreement of ideas. The most certain ideas are those that are pure intuition, without the intervention of other ideas. This is the clearest knowledge of which our human frailty is capable. What is sensibly, immediately evident is then the basis of all certainty (empiricism). A judgement  is when we put together or separate ideas from one another when certain agreement or disagreement is not perceived, but presumed to be so. Judgement yields opinion. Recall that Locke takes exception to his empirical view of certainty in the case of God and self.  

            Locke felt morality could be determined like geometry. God is the departure point of his morality as the Author of natural law. We can reach God’s law by reason and it is consistent with Scripture. Ethics is then conformity or disaccord of our actions with law. Thus, morality is not the perfection of man in light of his final end (Aristotle), but law precedes morality and morality is conformity with law. Our will is not oriented toward the good, but avoids pain.   If my will comes into conflict with the law in its avoidance of pain, it is moral evil.

            Locke shied away from absolutism and favoured moderation. In light of these tendencies, his political thought is marked by a view of tolerance, the separation of powers and human rights. His thoughts on the rights of men is not original, but came from Spanish writings.
Unlike Hobbes, Locke didn’t see society as an artificial way for men to live together. He viewed man’s primitive state as less violent than Hobbes. He believed that tolerance was above all necessary in the face of religion (really among Protestants, because Catholics and atheists he considered intolerable). He anonymously published Letter Concerning Toleration in Latin. His view relegated religion to the private sphere as the basis for tolerance. His thoughts were used in the Enlightenment, French Revolution and American Revolution.


10. Gottfried Wilhelm Leibniz (1646-1716)

            Leibniz very much labored for a reconciliation between empiricism and rationalism, between classic philosophy and modern philosophy. He adopted many ideas from different philosophers and borrowed their terms while changing the meanings. The main themes of his philosophy are the intellect, the body-soul bridge, and the freedom of God (existence of evil, sin). These themes are always influenced by his emphaisis on logic and his passionate pursuit of universal harmony. His idea of the universe was that of “a harmonious system in which there is at the same time unity and multiplicity, coordination and differentiation of parts.”


Logic according to Leibniz: Brief Overview
First we have to distinguish between truth of reason (verità di ragione) and truth of fact (verità di fatto). A truth of reason is a necessary, analytic proposition, either self-evident or reducible to a self-evident proposition. It is necessarily true, and this by the principle of non-contradiction (example: mathematics, logic). A truth of fact is not a necessary proposition—their opposites are possible, thus they are contingent, synthetic propositions. **If a truth of reason is true, it is necessarily true. If a truth of fact is true, there must be a reason that it is so. Truths of fact rest on the priniciple of sufficient reason, not on the principle of non-contradiction. They cannot be reduced to a self-evident proposition.
So far, this is comprehensible. Leibniz complicates things, however, by speaking of the freedom of God, who knows all truths as necessary, never contingent, because he knows all in one divine intuition. Simply put, Leibniz makes a point of declaring that God created the best of all the possible worlds. It was not, says Leibniz, that God simply made this choice, but that there is a sufficient reason. God cannot will evil, so this is the best possible world (“maximum of perfection”) that God could have made; in a certain sense, God necessarily created this world. At the same time, Leibiz staunchly maintains that God and creatures are truly free, even if their acts are predictable to a certain degree by the logic of truths of reason and truths of fact.


Nature of the Intellect
In order to reconcile the empiricist theory of knowing and the rational theory of knowing, Leibniz created a sort of “hybrid” intellect. We are familiar with the term tabula rasa. Leibniz, however, prefers the image of a slab of marble that has not yet been sculpted. In the same way that a sculptor must respect the original veins of the marble while working, the knowledge we have follows the predetermined “veins” of our intellect. This is solely a metaphor, however. Leibniz was not referring to the brain in an anatomical way. Knowledge is virtually contained in the mind.
The knowing process, then, is a combination of form and matter. The “form” (according to Leibniz!) is predetermined, already in the intellect, but not yet actualized. Thus the term to describe it is “formal predetermination.”  The “matter” is not matter as Aristotle thought of it, nor as Newtonian physics uses the term. Matter (according to Leibniz!) is concrete information perceived as sensation or experience. In this way, the requirements of empiricism (we perceive/sense, and nothing else) and the demands of rationalism (we know the ideas in the intellect) are both satisfied. In addition, Leibniz has resurrected the hylemorphic doctrine of Aristotle, or at least the words of it, and integrated them into modern philosophy.
Recall that, indeed, the intellect is the forma formarum, but not in a predetermined way. We abstract the forms from reality through the intentional knowing process. Leibniz would say that we apply them. “There is nothing in the intellect that has not been first in the senses…except the intellect itself.”  Later, this doctrine will have a great influence on Kant.


Body-Soul Problem; “Monads”
Leibniz’s solution to the correspondence or connection between body and soul is similar to that of Geulinex (recall: synchronized clock, no communication between the two substances) with a stong emphasis on voluntarianism.
According to Leibniz, all empirical things are composed of “monads”—a unity, a “one”, which is a simple substance. It is a predetermined reality, and the different monads are structured hierarchically. What we perceive as matter (reality), is actually the appearance of different combinations of monads, called by Leibniz “compound substances.”  It is a manifestation, an external aspect of the energy (inner tendency to activity and self-development) of the monads. There are other aspects of the monads that exist, but we do not and cannot know them. The appearance is real. In other words, it is not a mental construction that we place on reality.
Each monad is unique. They differ qualitatively and intrinsically from each other, not by extension or quantity, because they are spiritual substances. It cannot be generated or corrupted, but is created (and annihilated) only by God. The monads do not communicate or associate among each other. Material appearance, that is, corporal substances, are an effect of aggregation, not association. However, they are aggregates with a dominant monad which acts as the substantial form. The monads are completely independent from one another, but always in perfect harmony. This harmony is pre-established by God, who places all things in order according to his will (**volontarianism). Each monad is a microcosm which reflects the whole universe in all its perfections.
How does this explain man, who is corporeal substance but also spiritual?  Each man is also an aggregation of monads. However, man’s “dominant monad” is the rational soul or spirit. It acts as the substantial form and possesses a higher degree of perfection (and perceptions), accounting for the human being’s capacity for reasoning. Yet, the true unity depends more on universal harmony than on the individual monads, or the particular dominant monad. From a letter to Arnauld:

The union of soul and body, and even the operation of one substance [monad!] on another, consists only in this perfect mutual agreement, purposely established by the order of the first creation, in virtue of which each substance, following its own laws, agrees with what the others demand; and the operations of the one thus follow or accompany the operation or change of the other.

Thus, Leibniz’s theory is very similar to that of Geulinex (correspondence between the modes of the substance without communication); Leibniz himself compares God to a clockmaker, and the relation between soul and body to two perfectly synchronized clocks. The occasionalists believe that God is constantly adjusting and influencing the “clocks” that he has made, but according to Leibniz there is no need for that. They are always right on time—pre-established harmony.


The Problem of Evil
Given that all the universe has been established in and through a predetermined harmony and that God has created the best of all possible worlds, how does Leibniz explain evil?  He first distinguishes three types:
Metaphysical evilàimperfection
Physical evilàsuffering
Moral evilàsin
The latter two are connected to the former, that is, metaphysical evil. However, Leibniz emphasized human freedom and responsibility with regards to moral evil. The universal harmony as a whole explains physical evil. The problem is that the harmony is pre-established (God in the divine mind knows all things), and that pre-establishment is according to God’s will, meaning that he willed imperfection, or at least it was necessary that he create it. Leibniz does not sufficiently explain the role of human freedom (the will of man) in relation to morally evil acts and the dominant monad (soul), thus leaving his explanation open to severe criticism.




12. George Berkeley (1685-1753)

            George Berkeley was born in Ireland. He worked in a university environment and was a practicing Christian. His philosophy is thus permeated by a religious spirit and his knowledge of the classics. He also had a Neo-Platonist notion of God. He is an empiricist with a strange twist. Seeing the cynical, sceptical, atheistic environment of his times, he felt the way to save Christian thought was to negate that material exists in itself. He is known for immaterialism or anti-materialism.

Esse est percipi
Berkeley made a gnosiological proposition that being is to be perceived or to perceive: esse est percipi vel percipere. He believed that if matter or extension were considered independent of our minds, it would have divine qualities—infinite, immutable etc. (especially considering Descartes definition of substance). To him, if matter exists, either God is extension or an eternal, immutable, infinite, uncreated being exists alongside of God. Not wanting to give matter this autonomy, he said that spirits alone exist and matter is not independent of the mind.
How is Berkeley an empiricist?  He is an empiricist because of the way he connected perceptions and ideas. He challenged anyone to imagine or to conceive of a perception without an idea or to conceive of an idea without perception. Even according to materialists, he said, the mind perceives only impressions made on the brain, or rather, the ideas that accompany those impressions. The difference between Berkeley and other empiricists is that he said that only our perceptions or ideas of matter exist, and matter doesn’t exist if our minds don’t form ideas.

Berkeley shared Locke’s position on ideas. The objects of human knowing are ideas impressed upon our senses in the actual moment, or ideas perceived by paying attention to the emotions and acts of the mind (like Locke’s simple ideas). Berkeley also cited the existence of ideas formed with the help of memory and imagination (like Locke’s complex ideas). The latter ideas are always based on the former two.  


Things or substances
Things or substances, to Berkeley, are created by a constant and habitual combination of our ideas. We see certain sensations present themselves together, and we give them a name as if they were one thing. For example, I observe a certain color, taste, odor and form, and I indicate that collection of ideas with the name “apple.”  Then, I connect certain sentiments that arise in me in reaction to that collection of ideas, “apple,” like love, hate, joy, anger etc. Berkeley said it is impossible to separate these things or substances from perception—As I cannot touch something if I don’t feel that thing, it is also impossible to conceive of a thing in my thoughts distinct from my sensation or perception of it.

The spirit, instead, exists as the perceiver (whereas things or substances exist as perceived). Beyond the infinite variety of ideas we have, there is something that perceives those ideas and exercises various acts on those ideas—like to will, to imagine or to remember. This being that perceives and acts can be called “mind,” “spirit,” “soul” or “I.”  These words do not indicate an idea but something entirely different than ideas in which ideas exist or are perceived. This is why the existence of an idea consists in its being perceived.
How does Berkeley separate will and intellect?  He says that the spirit is simple, indivisible and active. In as much as it perceives ideas, it is the intellect. In as much as it produces or works on ideas in another way, it is called will.

What really exists to Berkeley are spirits. Human spirits, however, perceive punctually or intermittently.  All things would cease to exist if God didn’t constantly think of them. We join God’s constant perception when we perceive. In light of the reality of spirit, not matter, Berkeley felt that we need to overcome our tendency to assign real consistency to matter.


13. David Hume (1711-1776)

            David Hume was born in Edinburgh into a family of lawyers. He knew empiricism (Hobbes) but did not accept its materialism. Newton had an important influence on Hume, particularly his method and his “hypotheses non fingo” in regard to gravity. Hume also knew Descartes and Malebranche. He was anti-metaphysical and anti-religion. As a result, where other philosophical systems might appeal to God, Hume appealed to nature (particularly human nature).  He was a sceptic who combined his scepticism with custom and belief. Hume gave preference to practical and not speculative knowledge, and he sought to clarify and understand what the human mind can actually know.

Theory of Knowledge
a)Experience: impressions and ideas
            Like Descartes and Locke, to Hume, our sensible perceptions produce mental impressions. Our ideas come from these impressions. Once the impression passes, an idea remains like a weak impression. Thus, we know our impressions and ideas, not reality in itself. Each idea comes from a single impression—they are punctual or isolated impressions (atomism), not continuous. We link these impressions to form a succession, but the fact is, our knowledge is limited such that we don’t really know how or if these impressions relate. It is also noteworthy that, to Hume, our internal and external impressions are not of a different quality.

b)Association of ideas and their effects
            Because of our human nature, we tend to make associations among our ideas. To Hume, associations are like Newton’s gravitation:  we make them, but we don’t know why (like gravity exists as a unifying force, but we can’t explain why). We tend to create three principles by association:  similarity, continuity in space and time, and causality.  For example, we sensibly experience billiard balls hit each other and we associate the isolated impressions the billiard balls make with cause and effect. The reality is, we can’t know causality. Nevertheless, we depend on associations as the basis or “cement” of all our mental operations.

c)Abstract ideas
            True to empiricism, Hume believed that general ideas are nothing more than words assigned to particular ideas, giving them more extension. Words, then, are useful to stimulate our memory and imagination, helping us to recall individual things that are similar.  

d)Mental habits
            The punctual sense-impressions we receive, with the help of memory and imagination, help us to naturally develop customs and habits. While we can’t penetrate the reality of objects we know, we counterbalance this limitation by  believing in their existence. Customs and beliefs do not explain reality, but they do explain our faith in non-demonstrable principles (fideism).


e)Levels of knowledge—relationship between ideas and questions of fact
            Based on what we’ve seen thus far, to Hume, the human mind is weak and unreliable in what it knows. Therefore, even the most certain knowledge we have, which is that which depends on numbers and calculations, is really only probability, hence Hume’s scepticism.
He proposed three types of reasoning:  that which is based on knowledge, that which is based on proofs, and that which is based on probability. By knowledge, he intended the certainty born from ideas, for proofs he meant argumentation based on cause-effect—free of doubt and uncertainty, and by probability, he meant evidence that is accompanied by uncertainty.
Staying within Locke’s framework, Hume said true demonstrative knowledge depends on the comparison of ideas, while all reasoning of experience is based on matters of fact. Causal reasoning and all lesser degrees of knowledge depend only on the degree of vivacity that they reach in the mind according to accumulated experience, not on the clarity of relationships between phenomena.

Substance and “I”
            If we only know our sense-impressions (internal and external) and the ideas they leave in punctual way, and if the associations we make between our ideas are only beliefs and customs, what can we know about substances and ourselves?  Like Locke, Hume said we cannot avoid considering colors, sounds, tastes, figures etc., which don’t subsist in themselves, as inhering in a subject that sustains them.  Therefore, as we habitually infer a connection between cause and effect, we likewise infer a dependence of every quality on an unknown substance. The habit to imagine such a substance gives us the effect of having actually observed it.
As for the notion of “I,” Hume says the mind is nothing more than a collection of different perceptions, united between them by certain relations, with the false supposition that they are endowed with perfect simplicity and identity. We are, in other words, a bundle of impressions that follow in rapid succession, tied together by memory. This is the conclusion a good empiricist much reach. An “I” is not sensibly perceptible. The mind to Hume is like a theatre or a stage on which perceptions make their appearance. But to understand Hume, we must be careful not to think of the theatre itself as the mind, which would give it some kind of identity and unity. The mind is nothing other than the successive perceptions in themselves.


Moral Philosophy and Human Nature
The “I” Hume seemed to annihilate became the presupposed subject of his “Dissertation on the Passions.”  Hume’s morality is based on the sentiments our human nature provides us with, not on reason. Like his theory of our knowledge, we receive different internal impressions. From these impressions arise sentiments. The same impressions could be at the base of even contrary sentiments, depending on our position before the object (like another person) that produces them. Our will (like Hobbes) is nothing more than being conscious of a new movement in our body and a new corresponding mental perception. Nevertheless, Hume left a certain amount of room in his theory for deliberation. While reason alone cannot produce an action or will, nor can it block the will or prefer one passion to another, it can, give an impulse in a direction contrary to our passion.
The distinction between good and bad is not determined by reason, because reason is not capable of influencing our actions. Instead, the impressions at the base of our sentiments that arise in the face of an object determine our morality. From here comes the contemporary discussion that we can’t determine what man ought to be by reason in observing how he is (the is/ought question).


[14. J.J. Rousseau]

15. Immanuel Kant (1724-1804)

            Kant is the departing point for contemporary philosophy. He marks the end of the modern period, although he was greatly influenced by preceding philosophers, particularly Leibniz and Hume. He studied both rationalism and empiricism in detail and integrated both into his philosophy. Kant agreed with the conclusions of empiricism, particularly Hume, that by mere sense impressions, one does not arrive at causality, universality, necessity etc. Nevertheless, we use universal, necessary concepts. Kant sought to explain how we arrive at such knowledge. He saw in Hume a way to save religion while adhering to the obviously successful methods of Newton. Kant’s solution, which we’ll see, was to take faith and metaphysical concepts out of the realm of reason.
Kant’s philosophy was a sort of “Copernican revolution.”  He decisively changed the point of view of philosophy by turning from objects to the knowing subject. Descartes also did this, but with Kant, the object of study becomes not a globalized system, but a search for all knowledge that man can attain necessarily and absolutely. Kant departs from the question of the possibility of metaphysics. Can we have sure knowledge of God, freedom, or immortality?  From this line of questioning, he developed his Critique of Pure Reason, as well as the Critique of Practical Reason and, attempting to delineate how and what we can definitely, absolutely know with our intellect.


Kant maintained a very precise way of saying things, using different concepts and terms to express his thought articulately and consistently. To understand his system, it is of the utmost importance to have a firm grounding in his vocabulary.
1. a priori
meaning: preceding, coming before
Kant uses it as a necessary condition within the subject before knowledge, or a preceding condition of knowledge. We could call it knowledge underived from experience. Experience is mutable and without absolute points of reference. Therefore knowledge derived from experience cannot be absolute, nor can it be the same for all (universal). The a priori condition is the same for all men, allowing all to have universal, necessary knowledge. It is always our point of departure in knowledge.
2. necessary
meaning: something that must be
Kant uses it in reference to things that must be present in order to do a science, in other words, to have universal knowledge.
3. transcendental (synonymous to a priori)
meaning: initial conditions of possibility of every knowledge
These “transcendentals” are universal to every knowing subject; they are formal elements of pure consciousness (pure reason). Universality, according to Kant, belongs to the subjective sphere, not the objective or experiential realm.
4. analytic/synthetic
A commonplace understanding of these two terms would be separation/union, respectively. See the section below on Logic for Kant’s ideas.


A brief look at logic will help to explain the importance of the above mentioned terms.             There are two types of judgments:
Analytic judgments                     Synthetic judgments
In analytic judgments, the predicate is contained at least implicitly in the concept of the subject. For example, “All bodies are extended.”  No new knowledge is added, but we have separated or made explicit a concept already contained in the subject “body” by predicating “extended.”
Synthetic judgements affirm or deny of a subject a predicate not contained in the concept of the subject. For example, “All bodies are heavy.”  A new knowledge is added here. Synthetic judgments can be of two types. They can be purely factual or contingent and thus a posteriori. Or, they can be necessary and universal, and are thus a priori. Empiricists greatly object to synthetic, a priori judgments—are they really possible?  Can you affirm or deny that there exists a necessary connection between a subject and predicate not contained therein?  The answer is yes. For example, the sum of seven and five is twelve. The concept “twelve” is not contained in “seven,” “five,” or “sum,” but it is absolutely necessary.
Kant believed that all scientific, necessary knowledge must be made of sythentic, a priori judgments (giudizi sintetici a priori). We experience something new and unite it to an a priori element so that it is necessary, and then the  judgment is synthetic and a priori—and therefore valid. For example, I see one billiard ball hit a second billiard ball and the second billiard ball moves. The experience I have is that of a movement followed by an impact and a second movement. The a priori concept that I apply to this experience is causality. My judgment is not a result of an abstraction from this experience, but an application of a formal structure which already exists, i.e., a transcendental category, to an experience. The universal knowledge is the causality; the experience is not causality. The experience, in a certain sense, activates the universal knowledge that is already present in the structure of the mind.


Critique of Pure Reason
(please see the handouts given in class)
With a basic idea of what some of his terms mean, we can now examine Kant’s philosophy more in-depth. The Critique of Pure Reason is his explanation of the structures and rules that govern how we know. It is a systematic development of the transcendental categories and their applications. According to Kant, the mind does not conform to the object. If this were so, only experience would give knowledge, and it would never be universal. Instead, the objects conform to the mind, although not in the sense that the human mind creates reality. Reality exists in itself, but it is known through our a priori conditions.
If you look at the handout with the penguin on it, this might become clearer.
First we should ask: Does reality exist?  Yes. Something exists. However, the thing in itself (cosa-in-sè) is unknown to us. Thus, Kant denominates reality-in-itself “noumeno,” or unknown. The object of our knowledge is actually the phenomenon, or that which appears to us as a categorized object.
Second: How do we perceive?  By means of sensibility, objects are given to us. Sensibility provides us with “intuitions”—in themselves, these are unknown. They are like the raw material of perception. The a priori forms of sensibility are space and time, which are already filtering the intuitions. In a sense, we never receive “pure” sensation, but rather we receive sense input already formed by absolute space and time.
Third: How do we attain knowledge?  Up to this point we have a phenomenon. The thing-in-itself has already been left aside, and we are inside the subject. In the intellect, that is, pure reason, we have twelve a priori concepts of understanding (or categories) that are applied to phenomena. They are not derived from experience, but are applied to and govern experience. In themselves, these categories are empty and useless. They are pure reason, empty forms which must be filled in order for the subject to attain knowledge.
Kant’s theory of knowledge according to pure reason is, in a certain sense, hylemorphic. The matter comes from outside the subject, and is always unknowable in itself. The form comes from inside the subject, both in the sensitive realm (space and time) and in the intellectual realm (twelve categories). Scientific knowledge is the application of these forms to intuitions. This is  drastically different from Aristotle’s hylemorphic doctrine. Remember that Aristotle would say that the intellect abstracts the universal form after reality has been perceived by the senses (internal and external) and not the other way around. Both form and matter exist in the object, not in the subject. Further, the intellect is not pre-determined.

The categories of pure reason are only properly applied to phenomenon—that is, matter from the senses. The categories of pure reason cannot be applied to concepts. Anything outside of our a priori categories is not an object of scientific knowledge or reasoning—it is beyond the range of proof or disproof.  Because liberty, immortality and other metaphysical concepts are not phenomenon, the categories of pure reason cannot be applied to them. This is also very important for Kant’s theory on morality.


Critique of Practical Reason
Three ideas are absolutely critical for morality: God, immortality (or the immortal soul), and freedom. According to the critique above, none of these are the object of scientific knowledge because we do not have an intuition about them, in the Kantian sense. Instead, Kant calls these transcendental ideas. One could also include the universe as a whole, but we will not concern ourselves with this at the moment. We have no object within our experience that corresponds to them, yet the ideas exist. Kant calls these ideas “unconditioned principles of unity” (Copleston). The idea “God” is the unconditioned principle of unity of all objects of experience. The idea “soul” is the unconditioned principle of unity of all categorical thinking. Since they are not a source of theoretical knowledge of their corresponding realities, they do not partake of the sphere of reason, and thus can be moved to the realm of faith. They have important regulative functions in the practical or moral sphere. They are objects of faith, not knowledge.
Moral knowledge is a priori. There is necessary and universal truth in moral judgment. Practical reason is concerned with the production of moral choices, but the basis of obligation, or the reason that we choose correctly, must be sought a priori (not according to human nature or given circumstances).
The application of the transcendental ideas enters here. Their regulative roles come into play in the practical realm. They make reality more comprehensible for us and help us to think in an ordered way. Even better, we apply them to our experience and presuppose them in ethics. For example, the justice of this world is imperfect, but we have an idea of perfect justice, so it must exist somewhere, somehow. Morality in this world does not guarantee justice for all men. Therefore, to convince ourselves to act morally, we presuppose the immortality of the soul and freedom, because all justice will be fulfilled by God in the end. If we do not think in terms of these ideas, there is no foundation for ethics—it is useless. These ideas can be justified, but never demonstrated with pure reason.
What is it, then, to act morally?  The only morally good will is the one that acts for the sake of duty. Kant simply calls this a “good will (volontà buona).”  To act only in accordance with duty is nothing—one must act for the sake of duty to be good. For example, it is of no moral value to stop at a red light. For my act to be morally good, I stop at the red light because it is my duty to do so, and I know this and therefore choose to do it. The duty known by reason, or the moral obligation itself, is the a priori element. What is duty?  Duty is the necessity of acting out of reverence for the law, which is universal. What is the law?  Where does it come from?  The law comes from within the subject, but—it is a priori. It follows, then, that it is universal and not tied to any particular instance or circumstance. It fact, it cannot be—precisely because of its a priori nature. Thus, the end of Kantian ethics is justice, not the good, like Aristotle. Kant believed that an ethics based on the good was too easily subject to sentiments and self-interest. The only good is the disinterested good will which does its duty for the sake of duty. The person can hope for justice (to receive his proper due) according to the judgment of God (we see that this idea of “God” is necessary for Kantian ethics), but the impetus is always reverence for the law. For Kant, holiness or sanctity is to act as if one’s conduct does merit eternal justice. In other words: if there is a God, according to my conduct he will have to reward me with perfect justice.
Finally, how do we act morally?  The duty to act out of reverence for the law must be known a priori, independent from all experience. However, moral acts always occur in specific circumstances. Kant formulated three categorical imperatives, or unconditioned commands that must guide moral conduct always and everywhere. They are universal, equal for all men, rational, and formal. These imperatives are absolute, unconditioned for every person at every moment. There also exist hypothetical imperatives, which are conditioned by circumstances. They can be expressed as an “if…then…” statement. For example: If you want to lower your cholesterol, then you ought not eat eggs. Hypothetical imperatives are commanded as actions which ought to be performed as a means, and—acording to Kant—they are not a moral imperative.
For Kant, the only moral imperatives are the categorical imperatives, actions commanded as a good in themselves, which upheld the reverence for the law that is essential to morality. Kant gave three formulations of the categorical imperatives. The first two are very similar:
1)  I ought never to act otherwise than so that I can also will that my maxim should become a universal law.
2)  Act as if the maxim of your action were to become through your will a Universal Law of Nature.
The third formulations is the most famous one:
3)  Act as to treat humanity, whether in your own person or in that of anyother, always at the time as an end, and never merely as a means.
A maxim is a subjective principle of volition, a principle on which an agent acts as a matter of fact and which determines his decision. In other words, it is the principle for which a person does a specific act. Kant’s idea is that a morally good person’s principle for action or reason for action should always match these categorical imperatives.
Kantian ethics are useful for us in a certain way, especially the third formulation of the categorical imperative. They are, however, totally incompatible in theory with Aristotelian and Thomistic ethics. To act according to man’s nature is man’s proper end and his moral good, and his end is intrinsically linked to his happiness. All men seek happiness (eternal beatitude) above all, and the “eternal reward” that Kant seeks is a stripped down and protestantized version of that.


Source :http://www.pusc.it/fil/p_mercado/jamm/downloads_files/sf3english.doc

Source http://www.pusc.it/fil/p_mercado/jamm/downloads.html

Autor: Juan Andrés Mercado

Pontifical University of the Holy Cross
School of Philosophy


Didactical aid
Based on A. McGuan and M.C. Nutt classnotes (2006-2007)

Rome, September 2008



History of modern philosophy



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History of modern philosophy



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History of modern philosophy