History of Philosophy and Christian Thought - Lesson 16


Aristotle made a distinction between passive intellect and active intellect.

Ronald Nash
History of Philosophy and Christian Thought
Lesson 16
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Aristotelian Philosophy

Part 5

IX. Intellect

A. Passive Intellect

B. Active Intellect

C. Three Interpretations

1. Alexander of Aphrodisias

2. Plotinus

3. Thomas Aquinas

  • Thales and Anaximander were two philosophers in the sixth century BC that lived in Miletus.

  • Heraclitus and Pythagoras lived into the 5th century BC.

  • Any worldview addresses the subjects of God, ultimate reality, human knowledge, ethics and human persons.

  • Fundamental beliefs of a naturalistic worldview is that nothing exists outside the physical universe and that all things evolved.

  • Plato was a student of Socrates and lived into the fourth century BC. He opposed hedonism, empiricism, relativism, materialism, atheism and naturalism.

  • Plato described the universe as having three levels: the world of particulars, the world of forms, and the form of the good.

  • Plato's view of the universe was dualistic.

  • One of Plato's fundamental arguments is that the human soul is immortal.

  • Evaluation of Plato's arguments and comparison of Plato's philosophy with biblical theology.

  • Empiricism teaches that all human knowledge arises from sense experience. Rationalism teaches that some human knowledge does not arise from sense. experience

  • Aristotle was a student of Plato and lived in the fourth century BC.

  • Aristotle rejected Plato's doctrine of two worlds.

  • Discussion of Aristotelian philosophy as it relates to the incarnation.

  • Aristotle's philosophy as it relates to attributes of God and fundamental assumptions about psychology.

  • Aristotle made a distinction between passive intellect and active intellect.

  • Discussion of the strengths and weaknesses of the law of non-contradiction.

  • Discussion of the nature and substance of matter.

  • Hellenistic philosophy was an approach that was popular from the fourth century BC to the fifth century AD.

  • Stoics were determinists who believed in living according to nature.

  • Hedonism emphasized pleasure as the greatest good. "Eat, drink and be merry for tomorrow we might be dead."

  • Philo's philosophy was based on a synthesis of Stoicism and Platonism.

  • Implicit "Logos" Christianity is an underlying theme in the book of Hebrews.

  • Plotinus lived in the third century AD and is considered the founder of Neoplatonism.

  • Augustine is a Latin church father, is considered by many to be one of the most important figures in the development of Western Christianity.

  • Augustine wrote Confessions as an autobiographical work to record his experience as a sinful youth and his experience becoming a follower of Christ.

  • Augustine wrote to refute some heresies of the day by focusing on the concepts of faith and reason.

  • Augustine writes about the problem of evil and describes evil as the absence of good.

  • Augustine writes to refute Pelagianism by focusing on the biblical teaching about sin.

  • Augustine writes to refute Donatism.

  • The fundamental idea of skepticism is that no one can know anything. Augustine this statement contradicts itself because the skeptic is claiming that you can know that you can't know anything.

  • When Augustine wrote "The City of God," he had a linear view of history.

  • In Augustine's theory of knowledge, he says that eternal reason and human reason are two different levels of reason.

  • Augustine was personally convinced of the importance of divine illumination.

  • The intellectual background of Thomas Aquinas was influenced by the discovery of ancient manuscripts, the rise of universities, the rise of religious brotherhoods and the rise of Muslim philosophy.

  • Aquinas describes faith as whatever a human can know through special revelation, and reason as whatever a human can know outside of special revelation.

  • Aquinas attempts to prove God's existence.

  • Aquinas describes four kinds of law as eternal, divine, natural and positive.

  • The rationalists and empiricists set the stage for Kant and other philosophers of the modern era.

  • Kant argued that moral requirements are based on a standard of rationality he dubbed the “Categorical Imperative."

  • Kants two worlds are the phenomenal world and the noumenal world.

  • Discussion of criticisms and questions about Kant's ideas.

  • Similarities between Kant's ideas and postmodernism.

  • The dialectic is a central idea in Hegel's philosophy.

  • Ideally, Marxism begins with class struggle, then revolution, dictatorship of the proletariat, withering away of the state, and a utopian classless society.

  • Discussion of four faces of Marxism.

  • Nietzsche proclaimed that, "God is dead." His cure was to live life knowing there is no ultimate meaning. Kierkegaard emphasized a worldview based on true faith.

In this class, you will explore the rich history of philosophy and its relationship with Christian thought. The course begins with an introduction to the definition and importance of philosophy in Christian theology. You will then delve into the evolution of philosophical thought from the Pre-Socratic era, through the Classical Greek philosophers, and into the Hellenistic period. As you progress, you will discover how early Christian thought emerged and developed during the Patristic period, with a special focus on Augustine. The class continues with an examination of medieval Christian thinkers, such as Anselm and Thomas Aquinas, and concludes with an analysis of modern philosophers like Descartes, Kant, and Kierkegaard, and their influence on contemporary Christian thought.

Dr. Ronald Nash

History of Philosophy and Christian Thought



Lesson Transcript


In his in his book on Psychology de Anima Book three, Section five, and in the immediate and surrounding pages of the day, Anima Aristotle makes a distinction between two parts of the human intellect. Now, this is very slippery stuff here. We've given you his view of the soul and explained it in terms of life and the three kinds of life and so on. If you read all of Aristotle's psychology, there seems to be a definite push, a definite portion, Aristotle, against any human consciousness after death. I mean, the first few times that I read Aristotle, I said, this guy, if you if you buy into Aristotle's system, there's no way of believing consistent with the system. There's no way of believing that human consciousness, human personality exists after death. What we're going to do during this session is look at a strange passage in Book three of De Anima, in which Aristotle seems to open the door. How wide the crack is is up to you. He seems to open the door to a way in which. Some kind of human survival after death is possible. Basic to understanding his view here is grasping a distinction he makes between two aspects two sides, two parts of the human intellect. He calls them the passive intellect and the active intellect. And incidentally, once we understand this difference, you'll be in you'll be in better shape to understand the basic structure of a Aristotle's theory of knowledge, which was the other part of his system that we were going to explain today. Now, let me draw up a human face on the board here, and we'll put a smile on this person because he's studying philosophy.


[00:02:56] He's very happy about this. And then inside of this person's head, we're going to draw a little box that we've divided in half, and we're going to use this the two parts of this box to illustrate what Aristotle calls first the passive intellect that's over here. And then this would be the active intellect. Now, Aristotle never draws a picture like this anywhere in his writings, but this kind of illustration may be helpful to you. The word passive, as in passive intellect, carries with it the idea of reception receiving something and what is received in the case of the passive intellect is information. Okay, so we're going to draw a line from outside this person's head into the box that represents the passive intellect. What is received in the passive intellect is sense information. Information through the senses, sight, touch, smelling, hearing, whatever are forgotten. Anyway, the five senses. Okay, so outside of the brain, I'm going to draw a picture of a tree. Beautiful picture of a tree. A blue tree. As only I can draw it. Okay. And then what you get eventually inside the passive intellect is what Aristotle calls a phantasm. Now, I apologize for giving you that language, but if I oversimplified everything, you'd think this was too easy. C a phantasm. That's Aristotle's name for what amounts to a sense impression. A picture, sensible picture. In other words, as you look around the room, this room, you're receiving all kinds of sense data pictures. I mean, the picture of the person sitting next to you, the picture of your professor, the picture of the scribbling on the on the whiteboard and all of that. That's all received through your senses in your passive intellect. Aristotle says what is in your passive intellect is not yet knowledge.


[00:05:34] What you get in your passive intellect is only potential knowledge. Yes, he actually uses that term. It is potential knowledge, and thus it is somewhat analogous to the matter of knowledge. Okay. The stuff of which knowledge is made the matter. Okay. Now, the reason why the information, the pictures, the phantasmagoria and all of this, whatever you want to call it in your passive intellect. The reason why it's not knowledge is because it is only particular stuff. Remember Aristotle's? I'm sure remember Plato's point that you can never have knowledge of particular things. You can only have knowledge of the universal. Aristotle is, on this point, at least very close to Plato. You can only have you can't have knowledge of particular things. You can only have knowledge of a form, the form. But for Aristotle, the form is not. In some other world, the form is not separate from particular things. It's always a part of particular things. Where is the form of a desk Answer? It's present in every particular desk. Where is the form of a cow? It's only present in every particular cow as the essence of a cow. And so on and so on. Okay. So in order to get from potential knowledge, that is the sense information that is received by the parts of intellect. The mind must do something to this sense information. And here's what it does, and I hope you see the irony of this, and I hope you see the beauty of this. The mind must abstract from these particular examples of things. The common element, the universal element. Now I'm going to sit for a moment and ask a question. Does the language I've just used remind you of anything else that you've already read in this course? Give me chapter and verse.


[00:08:12] And if you say the book of Hezekiah. 316, you're a dead duck. Okay. What have you read earlier in this semester that corresponds precisely to what Aristotle is doing here? Plato's phyto feto. Let's say feto just for the heck of it. Okay. Plato's feto in his discussion of how we come to know equality Now, when we were reading the FETO or my account of the FETO in chapter three, I told you at a particular point to write these words in the margin of your FETO. I said, Right empiricism. And then add in parentheses. Hiss. Boo. Put thumbs down. Okay. And I also said to write a name there. Whose name did I tell you to write? Aristotle's name. What Aristotle is telling us to do in Book three of Diana is precisely the position that Plato describes and attacks in the feito. Here it is. How do you come to know equality? Answer You see particular things. And where are those particular things? You see them in the passive intellect. Here are those three sticks. Four sticks. Here are triangles. Here are circles. And then what does the mind do? It abstracts. That's the key word here. That word describes the line between the passive and the active and like the mind abstracts. What is common to all of these particular things? And all of a sudden you get the notion of the equal itself. So strictly speaking, knowledge for Aristotle always has its its object, the form, the universal, that which is common and the way but the way you get it is through abstracting the common element from information of the senses. This is empiricism, and it makes me, it makes me we have to think that, you know, bright people can't rise above this empiricism.


[00:10:39] And what I would do here if I had Aristotle here with my hands around his throat or something. No, that wouldn't. I wouldn't do that. Put my arms around his shoulders in a sanctified kind of way, shake him a little bit and say, Aristotle, don't you realize that you already you already knew that these sticks were equal, that these triangles were equal as they were present in your passive intellect. You don't get this knowledge of the universal after the fact. You know it before the fact. Now you're ready for one of them for another great excursion. End to broadcast excellence. Now that's Rush Limbaugh. But that's all right. That applies here, right? Because this is broadcast excellence, too. I'm going to write on the black on the white board a sentence from Day Animal Book three, Section five, The Active Intellect. I suggest you memorize this. The active intellect is separable. And get this, friends immortal. And without it, nothing. Thanks. Wow. Now, look at this sentence. Because it appears to contradict what I, ah, earlier told you about the drift of Aristotle's thinking throughout the whole of the day animal. But if you start reading de Anima ad on the first page and keep reading through there, you're you're. You're almost pushed in the direction of believing that when the human body dies, human existence ceases. There is no conscious existence after death. But all of a sudden. At the at the end. The third part of the book, the last part of the book, Aristotle writes the sentence. The active intellect is separable. Separable from what? The only meaning that makes sense is that it is separable from the body. I think separable. And it is immortal. Means it doesn't die. And without it, nothing thinks.


[00:13:09] Now, this sentence was so puzzling to later students of Aristotle that it gave rise to three competing conflicting interpretations. It gave rise to three conflicting, competing interpretations. I'm going to identify and explain those three competing interpretation. Now, here again is what made these interpretations necessary. It looked like Aristotle was contradicting himself. Okay. What does this mean? Another thing that's important about these three competing interpretations of Aristotle is this They ended up identifying the three major systems of philosophy during the Middle Ages so that when you understand these three interpretations of this one sentence in Aristotle, you are in the middle of the three most important systems of philosophy after Aristotle. Okay. Now, I'll give you these views chronologically, and then I'll tell you what I think may be the best interpretation. The first interpretation of this strange text appears in the writings of a man you've never heard of until today. Alexander of Aphrodisiacs. Am I right? You've never heard of this man before. Now, this is spelled in two ways. Sometimes there's an H added in here. Aphrodisiacs. Who was this guy? He lived around 200 A.D.. I know only two things about him. I've, you know, I. Every once in a while, I get a hankering to know more about Alexander of Aphrodisiacs, and then I'm. I'm detour detoured. I have something that interrupts me, like a baseball game on television or something else like that. This man, there are two things I know about him. Number one, he was called the greatest of the Aristotelian commentators, at least at this period of time. I would say maybe Aquinas was a better commentator on Aristotle, but for the period of time, 200 years after the birth of Christ, Alexander of Aphrodisiacs was respected as the greatest of the commentators.


[00:15:45] Add on say much about him. All right. Secondly, I've read that he was a Christian. Both those comments are in my memory from stuff that I passed over 30 years ago. You know, I can't I'm more I'm more confident that he was a great interpreter of Aristotle and he was a Christian. But anyway, that's what we were told. Now, here was Alexander of Apprentices interpreter reputation. He said the active intellect in the animal Book three, Section five is God. Wow. Now let's think about that. The active intellect is separable. That means it's different and distinct from anything related to a human being. Okay. And it is immortal. Well, Scripture says God is immortal, in fact. I've already told you the word immortal in the New Testament as applied only to God and to a human being. After the resurrection of the body, then shall this mortal put on immortality. And without it, nothing thinks so. So, you know, if we assume that Alexander of Aphrodisiacs was a theist that is believed in us in a single personal God, his view seems to imply that. What makes it possible for human beings to attain knowledge is some presence of or activity of God in a human being. Okay. Well, what's more fascinating to me is that this same general interpretation is picked up much later by Augustine, the great Christian philosopher who died in 430 A.D. and who was most famous for his theory of Divine Illumination theory of divine illumination. Now, so far as I know, only one philosopher, so far as I know, only one philosopher in the history of the whole world, in the history of ideas, has noticed this kinship between Alexander of Odysseus and Saint Augustine. Humility prevents me from naming that one philosopher.


[00:18:12] But I'll tell you this you'd never know the name of that guy if you went to any other seminary. All right. This is it right here. And if you want to know how that works out, well, we're going to talk about Augustine later on. Or there. I did write a book about Augustine's theory of knowledge. It's called The Light of the Mind. It's in the books. It's in the library. The second interpretation of the act of intellect comes from Plotinus. Yeah. And you have. We have a whole chapter on Plotinus in your intro book. I think it's chapter five. Yeah. Plotinus died in 270 A.D.. He was not a Christian. He was definitely a pagan. And we'll look more at plotinus, his whole system of philosophy. And in a few weeks plotinus his answer was The active intellect is a kind of cosmic noose. Now, I know that language doesn't mean much to many of you, but you will know what that means in a few weeks. In other words, for Plotinus, the active intellect is not necessarily God. It is. The mind of God. It is the noose of God. So here again, this is something above a human being. This is something independent of a human being. Only in this case, in the case of Alexander, it's God in the case of Plotinus. It's a kind of cosmic news. And I guarantee in 3 to 3 weeks, you'll know exactly what that means. Now, this view then gets picked up later in the Middle Ages by a muslim thinker named Averroes, a very Veronese who lived around. I think he died around 1200 A.D. And a Veronese, even though he was a muslim, was very much under the influence of Plotinus thinking and was basically teaching Plotinus view of God within the Muslim Muslim faith.


[00:20:30] He got into some trouble. Now, the third interpretation this is a huge system. This is a huge system. Now we come to the third interpretation. It's Thomas Aquinas. Now, in a matter of three, four weeks, I'll give you a whole background. In fact, I'll talk about the relationship between a very always and Thomas Aquinas. And you're going to find that exciting and you're going to want to wonder. You're going to wonder why no one ever, ever made a movie about that stuff. Now, Thomas Aquinas, for reasons that will explain and in several weeks. Thought that the active intellect was a part of each and every individual human being. You have an active intellect. I have an active intellect. And Aquinas taught that active intellect is the part of us that will survive the death of our body. That active intellect performs the same basic function as well as the soul does. See? The difference is that for Aquinas, For Aristotle. For Plotinus soul is not the kind of individual substance that Plato believed in. It's it's more closely related to the intellect or to the mind. All right. So I'm not going to write any more on the board here. Now, which of these is the best interpretation of Aristotle and I here? All I can do is cite the authority of some highly respected Roman Catholic scholars. When even Catholic scholars admit that Aquinas interpretation is wrong as an interpretation. I think that carries some weight. The reason why it's wrong as an interpretation is because it, it, it it bumps into this this this conflict with so much that Aristotle had said earlier. I'll also explain in a few weeks that Aquinas had some political reasons for advancing this thesis that had perhaps more to do with this than theology or philosophy.


[00:22:47] And so and I really can't. I'll tell you where to go if you want to. If you want to read some Roman Catholic reasons to support this. But the the the position of most Roman Catholic scholars today, whom you must understand under normal circumstances would side with Aquinas on just about everything. The view of most Catholic scholars is that this may this is probably what Aquinas meant, and that would be the position of Plotinus and a very wise. Now, frankly, that gives me an enormous Excedrin headache because I don't see how that's the least bit consistent with Aristotle either. But I don't want I don't want to take that, you know, I just don't want to take the time to fight that out here. If you want to read more about it, go to the History of Philosophy book series written by Frederick Copleston, who's a Jesuit, S.J. History of Philosophy. This would be, I think, in volume one of his history of philosophy, and just see if Copleston gives you any help there.