Aristotle and Kant on the Validity of Metaphysics as a Science

 Introduction

Immanuel Kant and Aristotle both explored the possibility of whether Metaphysics could be studied as a science. Both answer in the affirmative, although Kant wishes to make a qualification: namely, that for metaphysics to exist as a science it needs to find an a priori foundation. I will be drawing from two main sources. From Kant, the “Prolegomena to any Future Metaphysic that can Present itself as a Science”. From Aristotle, the “Metaphysics.” In this essay, I will compare and contrast both thinkers perspectives on whether and how Metaphysics can be studied. Following this compare and contrast, I will look briefly at the implications for both perspectives. 

It is worth noting at the outset what each author means by science. They do not use the term in the way we do today. Bennett, the editor and translator of Kant’s work, says, “throughout this work, ‘science’ means ‘branch of knowledge that is theoretically organized, highly structured, and soundly based’.” I think that Aristotle would accept this definition, especially when contrasted with our modern notion of science. It’s not that Kant didn’t know about modern science. In fact, he spends a section of the work discussing their types of knowledge as well. He describes natural sciences as empirical and physical. However, science more generally is a body of knowledge, whether empirical or theoretical. 

I will begin by discussing Aristotle’s thoughts on metaphysics as a science. Next, I will discuss Kant’s arguments about the subject. Then, I will compare the two thinkers. Then, I will contrast them. Finally, I will look at the implications of both thinkers on metaphysics as a subject before concluding. 

Aristotle on the Necessity of the Study of Being

Aristotle begins his treatise on metaphysics by saying that “all human beings by nature stretch themselves out toward knowing.” That ultimately, the wise man wants to know the causes of things. He explores how some in his day sought this materially, and others mathematically, and others formally, but these accounts fall short, to varying degrees. 

To gain this knowledge then, Aristotle thinks, the wise man must study “the first causes of being as being.” He proves this in the following way. He says that being is meant in multiple ways. However, all of the meanings of the term approximate the actual meaning. He gives an important analogy of health. That there is health in the individual, but there is also health in the blood samples, and health in his food, and health in his medicine. All of these secondary uses of the term are only meaningful, though, insofar as they are ordered toward the individual. In the same way, being is in the things that are. And so we can say that being is both in substances and accidents, and in everything that is, but only if we are willing to treat the term being analogously. 

Given that being is in things actually, there are a multitude of types of being. And since these are all types of the same thing, being, it follows that there is a primary philosophy that studies the cause of this being. Just as in other subjects there are sub disciplines which work their way back to the primary discipline, so there must be with the different philosophies (which study different types of being), but ultimately, there must be a First Philosophy which studies the cause of being as being.   

After defining terms in Book 5, he returns to the subject of what is the science of Being as Being? Here, he goes through the highest disciplines and their relationship with matter. He says that natural philosophy relates to things that are material and in motion. There is also mathematics, which studies immaterial things, but only insofar as they exist within material things. But, he thinks, “if there were no other independent thing besides the composite natural ones, the study of nature would be the primary kind of knowledge; but if there is some motionless independent thing, the knowledge of this precedes it and is first philosophy.” 

Since there is being that is eternal and immaterial (in thinghood) we need to have a study of being as being, and so we need Metaphysics as a subject of study. By thinghood I mean the immaterial form of a thing. We recognize a horse as horse, because we recognize it to be the type of thing that it is. Now this thinghood is not in the matter that makes up the horse, but is an intellectual notion, and so is immaterial. It is because there are these immaterial independent things that this subject is needed; without them, Aristotle thinks, we could stop at Philosophy of Nature. 

He goes on through the next couple books to show that this being as being is primarily meant by thinghood (substance), and that this is best expressed in being at work (activity) as opposed to potency. This being at work is what drives things to fulfillment. As young children we know that we are meant to develop into fully thriving adults, for example. Similar to how the problems of motion are solved by having an Unmoved Mover (God) in the Physics, the problems of forms are solved by having an eternal, motionless and intelligent cause (God) that explains where this thinghood comes from in the latter books of the Metaphysics. Notice that the object of study is not God, but that the object of study is being, which is only explained by God, similar to how the Physics studies motion, which can only be explained by God. 

Kant on How Metaphysics Can Be a Science

Kant begins his Preliminaries (Prolegomena) with a question for his readers to ponder. Is “such a thing as metaphysics even possible.” After all, sciences get “universal and lasting approval,” and it seems that metaphysics comes and goes and changes throughout time. So are we just pretending that it is a science, when it is really just pretense? He adds that other sciences that have been around for as long have only developed, whereas metaphysics seems to “circle the same spot.” He raises a further problem using the thought of David Hume. He thinks that, since Hume, the relationship between cause and effect has been ruptured, and so knowledge must start from a priori (theoretical, or non experiential) principles. Or, in Kant’s own language, metaphysics must be validated as a subject by pure reason. 

And so, Kant’s goal in this work is to “once and for all reach a conclusion about the nature of this would-be science.” He wishes to start over and give the principles necessary to build metaphysics in a way that it can actually be a science, and not wishful conjecture. And so, in Kant’s eyes, for metaphysics to be a science, it must be able to operate off of the principles that he will lay out throughout the rest of the work. “Someone who undertakes to make judgements in metaphysics...must satisfy the demands I have made here, which he can’t do by rejecting them, so he must either adopt my solution or thoroughly refute it and put another in its place.”

With this, he goes on to lay the rules for future metaphysicians. He begins by laying out the possible sources of metaphysics. He says that this knowledge must be a priori, or based on pure reason. Thus, he eliminates experience from being a source of metaphysical knowledge. Second, he distinguishes between analytic and synthetic a priori judgements. The former don’t seek new knowledge, while the latter does. While mathematics and natural science can use and seek both types; metaphysics must only seek synthetic judgements, and only use (not find) analytical judgements. And so, for metaphysics to exist, it must only seek synthetic a priori knowledge.

Following this, he seeks to see how is it possible to attain this kind of knowledge? He goes on to give examples from mathematics and natural science before turning to metaphysics. He goes on to describe different ideas that we have that are often considered metaphysical . First is the psychological idea. Next, is the cosmological idea. Last, is the theological idea. The first two are problematic because they use reason beyond experience. The last is problematic because it is too conjectural, it is used to make sense of the world, but is without evidence. 

And so, he lands on the position that metaphysics is possible, but riddled with traps. It needs to be built on: a priori concepts, classified by their different senses, listed completely, analyzed through all consequences and must prove that synthetic a priori knowledge is possible, and show the correct boundaries in which pure reason can be conducted. This can only be done by healthy criticism, Kant thinks. 

Comparison Between Perspectives

In laying out both thinkers' perspectives on the possibility of metaphysics as a field of knowledge, we see a few similarities. First, both thinkers appreciate the fact that metaphysics is related to being. Second, there is an epistemological element to metaphysics. Third, both situate metaphysics alongside natural science and mathematics. I will treat each of these points individually. 

The first point of common ground is that both thinkers relate metaphysics to being. As we saw above, Aristotle sees metaphysics as the study of being qua being. Similarly, Kant says that in metaphysics “you will find the knowledge of the highest being and of the world.” As we will see in the contrast sections, there is a radical difference in how these thinkers interpret the actual subject of study of metaphysics. However, it is clear that both perceive being to be a fundamental end of the subject. The question is whether it is being, in and of itself, or the highest being (God)? Put in another way, are we seeking the ground of being, or the pinnacle of being by which all things participate in?

The second point is that there is an epistemological element that needs to be addressed in seeking to define metaphysics as a subject. One key element of Kant’s Prolegomena is that he is defining the epistemological parameters by which Metaphysics can be possible. Similarly, Aristotle makes pains throughout his Metaphysics to show in what ways this study can be possible. Again here, we will explore differences, but it is clear that both thinkers believe that you need to have the proper epistemological roots in order to be able to build the study of Metaphysics. 

The third similarity is that both thinkers approximate metaphysics near mathematics and natural science in their situating it as a discipline. Kant spends individual sections on mathematics and natural science and how they are epistemologically possible. In doing this analysis, he is paving the way to show how metaphysics can be possible. And so Kant see’s that just like mathematics and natural science are possible subjects of inquiry, so can metaphysics if it fits within the synthetic a priori knowledge parameter that he sets. Similarly, followers of the Aristotelian-Thomist tradition have long interpreted the three speculative sciences as physics (philosophy of nature), mathematics, and metaphysics as the three speculative sciences which are distinct from natural science. And so both philosophers describe these subjects as related, even though they would almost certainly order them differently. 

Contrast Between Perspectives

There are many differences between these thinkers. First, the difference in epistemology (both in emphasis and in its role in metaphysics). Second, what each takes to be the subject matter of metaphysics. And third, the utility of metaphysics. I will treat each of these individually. 

The first difference can be split into two parts. First, in the form of epistemology that is being employed by each philosopher. They differ in whether knowledge can be derived from sense experience, whether knowledge can be derived a posteriori and whether we can know by thinking about thinking itself. Second, in how epistemology is made to take the place of metaphysics in Kant’s view, whereas it is only a building block for Aristotle. I will treat each of these individually. 

The first part of the first contrast is how each philosopher's epistemology informs their view of Metaphysics as a science. Father Thomas Joseph White comments, this is “the true point of conflict between Aristotle and Kant...whether or not we are naturally capable of true knowledge of beings and their intrinsic and extrinsic causes qua being, or whether such claims to knowledge are in fact merely the a priori constructions of reason.” For Aristotle, our sense experience is what informs all of our knowledge. And so, since we can trust our sense experiences discovery of real being, Metaphysics is a valid subject of inquiry. Kant, on the other hand, thinks that only through pure reason, a priori and synthetic, can a given discipline be trusted. Since Metaphysics, up until now, has not relied on these notions, it is unreliable and not yet a valid subject. For Father White this difference in epistemology is the largest divide on this issue. 

Another element to this contrast has to do with what kinds of knowledge are valid. Kant expresses that metaphysics can only be possible if it is sought a priori. Aristotle, on the other hand, thought that knowledge came about through the senses. The sensory information that we take in goes to the memory, and from there can be reformulated for the reason through the phantasms (like imagination). From there, the intellect can use this sense information to group, gather, and build off of these phantasms. This is clearly an a posteriori approach since we are relying on sense information from our experience to develop rational inquiry. 

The view that we can think about our thinking in the highly analytical way that Kant argues for, is something that Aristotileans like St. Thomas Aquinas would push back on. Rather than being able to analyze our thinking as such, Aquinas would say that we can only analyze our thinking as it is in act, or when it is in the midst of looking at an external object. So, Aquinas, and presumably Aristotle, look at epistemology’s role in the exact opposite way as Kant. Rather than us needing to prove the usefulness of sense experience in our knowledge, sense experience is the very vehicle by which we can know things. We only come to know things by observing them, and then abstracting information from them. And so this is one radical difference between Kant and Aristotle. 

The second point related to epistemology has to do with epistemology’s role in metaphysics for each philosopher. As Father Thomas Joseph White says of the effects of Kant’s Prolegomena, “Metaphysical ‘science,’ then, is explained in terms of a necessary transcendental ‘illusion’ of pure reason permitting a theoretically coherent ordering of the subject’s sensible experience.” So, for Kant, metaphysics (as it existed before him), was uncareful organizing of things that we don’t have the logical right or power to organize. It is illusory. And so ideas psychological, cosmological and theological that were derived from this uncareful Metaphysics cannot be trusted. 

Because Kant has this perspective on knowledge, he revolutionized how philosophers before him are interpreted. As White continues, Kant’s work “shifted the meaning of metaphysics from being an explanation of the structure of the real to explaining the immanent nature of human transempirical reason.” And so even former philosophers are “now interpreted through the grid of an anthropological epistemology.” This is a radical shift from Aristotle’s study of being qua being. Aristotle thinks that we can know things they way they actually are. As Joe Sachs notes when Aristotle introduces the law of contradiction, “this formulation makes it clear that Aristotle considers [laws of thought] principles that govern being rather than thinking.” Where Kant takes these principles to be purely epistemological, Aristotle thinks that these are principles of reality that govern being, and are not just products of human thought.                       

The second difference between Kant and Aristotle on Metaphysics as a science is what the object of the science is. As I mentioned above, these two are similar in saying the end of the subject is being. They are different in what they mean by this, though. As noted above, Kant thinks that this science seeks to work towards a highest being. This seems to stem from him treating being as a genus by which all other types of being participate in. This is because Kant has dismissed the possibility of an analogical understanding of God, and so the Being of which God is the cause must be the exact same type of being that all other types of being participate in. 

This is different from Aristotle who thinks that metaphysics seeks being itself, or being qua being as its subject. While ultimately the answer to this question of what is the cause of being, is God, the object of the science of metaphysics is to find the cause of this being. The most primary type of being is thinghood, which is immaterial, although it exists in the particular things in the world. And so, being is not a genus for Aristotle, because you can’t have a specific difference for a subject that is as diverse as being. 

Also of note here, is that Kant is presupposing the object of metaphysics. His Prolegomena never explains why this is the subject matter of metaphysics, only states that it is. And so, in conjunction with the last point, if Kant is presupposing that the subject of metaphysics is God, while ruling out the possibility of reasoning from sense experience, he is largely assuming his answer that metaphysics requires a priori demonstrations that God is the highest possible being. 

The third difference to be elucidated is on the utility of the subject. Kant has a preconceived notion that sciences should be useful. In describing the problems with metaphysics from the past, he thinks that if we don’t give these guidelines for how this subject can be done, it has no chance “of being useful and wise.” This is the complete opposite of Aristotle's conception. He describes how knowledge sought for its own sake is the best. He gives the example that the mathematical arts were constructed not for use but from contemplation in leisure by Egyptian Priests. Rather than utility being the motivation for speculative science, leisure and contemplation are the true basis for the speculative sciences, but most especially for wisdom which we are seeking in metaphysics. It is only in this leisure and contemplation that we can seek “knowledge concerned with certain sources and causes (982a2-3),” which is the very definition of wisdom for Aristotle. 

Implications of Viewpoints

Before concluding, I will explore the implications of inhabiting either of these perspectives on metaphysics. I will start with Kant and give Aristotle the last word. There are 3 implications of Kant’s views of Metaphysics as a science. First, metaphysics as a study is now stripped of its power to reach any conclusions. If Aristotle is correct, that all knowledge begins in the senses, but Kant is correct is saying that a posteriori knowledge cannot be used to build a foundation for metaphysics, then metaphysics is largely impossible. 

This leads to a second implication. Since metaphysics has lost the ability to study being and its ultimate cause, you cannot prove God’s existence. Kant keeps God as a regulative notion or ideal that is useful for us, but we don’t have rational evidence that He actually exists. This leads to 2 minor implications. First, ethics turns from the pursuit of happiness according to your nature and growth in virtue, to fulfilling moral obligations to your neighbor based on the Kantian Imperatives. Second, transcendence turns from an upwards path seeking communion with God to a forward path towards building a utopic future in which there is a Universal Secular State. 

The third implication from Kant’s emptying of metaphysics is that Math and Science become the two paths for the intellect to seek truth. Since these have an a priori foundation for their pursuit, the knowledge that they obtain is actually reflective of reality. And so metaphysics, and philosophy more generally needs to concede to science and math as the vehicles for man to seek truth. 

However, if Aristotle is right that metaphysics is a valid subject of inquiry by which we seek the cause of being qua being, there are a different set of implications. I will present three. First, is that the answer to the question of what is the cause of being qua being is the Unmoved Mover who is the source of all motion (from the Physics) and the source of all being (from the Metaphysics). 

From this we see a second implication, that we can see that God is not only the cause of being in the past, but is presently causing anything that has being right now. And so God is not some foreign cause who caused, but is rather causing all that is in being right now. This leads us to a God who is personal and attainable if he were to reveal himself. 

Thirdly, if Aristotle is right about their being a study of being as being, this has a major implication for you and me. Since “wisdom is a knowledge concerned with sources and causes,” and we can discover the cause of all being, we are capable of attaining wisdom. As Aquinas puts it, “Wisdom considers the highest causes...wherefore it rightly judges all things and sets them in order.” By knowing the ultimate cause of all things that are, we are able to subordinate all of our knowledge rightly, and so live a well ordered life. 

Conclusion

In this essay, I have compared and contrasted the perspectives of Aristotle and Immanuel Kant on whether there can be a study of being, or metaphysics. Aristotle answered in the affirmative, as did Kant, although Kant gave very stringent qualifications that make the study largely impossible. In comparison, I showed that both understood metaphysics to be about being, I showed that metaphysics has an epistemological dimension, and I showed that metaphysics needs to be situated alongside other disciplines. In contrasting, I discussed that Kant largely turns metaphysics into an epistemological enterprise, whereas Aristotle used epistemology as a tool to study the subject as such. Also that they use vastly different rules in guiding their epistemological basis for such an inquiry. Secondly, I discussed their different objects of metaphysics. For Kant, metaphysics seeks the highest of all beings, whereas Aristotle’s object for metaphysics is the cause of being as being. Thirdly, I differentiated the utilitarian perspective of Kant against the leisurely contemplation of Aristotle in regard to this subject. And so, we have seen two of the largest thinkers on the subject answer the question of how metaphysics can be studied as a science.

Compare and Contrast Between Descartes and Aristotle on the Soul

Introduction

The goal of this paper is to compare and contrast the descriptions of the soul as put forth by Aristotle and Rene Descartes. The main works I will be drawing from are the “Meditations on First Philosophy” by Rene Descartes and “On the Soul” by Aristotle. These two thinkers have had a massive impact on what we mean by the term soul. Despite their differences in era (one ancient and one modern), a detailed comparison can get to the root of what we mean by the soul. By contrasting these two thinkers, we can gain an even better appreciation for the implications of their beliefs on anthropology.

I will begin by outlining Aristotle’s definition of the soul, and how he differentiates types of souls. Next, I will describe Descartes' understanding of the soul. With this basis, we will be able to compare the two thinkers perspectives. Following this, I will contrast their thoughts. Finally, before concluding, I will look at the implications of these differences. 

Aristotle On the Soul

Aristotle lays out his treatment of the soul in 3 books. In Book 1 he lays out the theme and describes the views of his predecessors. In Book 2 he seeks to define what he means by the soul and to give a general account. He defines the soul as “substance in the sense which corresponds to the account of a thing.” He goes on to give an analogy. He says that if you consider an axe to be a living thing, its soul is what helps it continue to be an axe, once the axeness of the axe has left it, the soul is no longer present in it. Further, he gives an analogy of the eye. Since the essence of the eye is sight, when an eye is not able to see, it’s an eye in name only, because the soul or essence has left it. He makes clear at the close of Chapter 1 that the soul and the body are both necessary to make a thing alive, although he allows for the possibility that certain powers or parts of the soul might be able to exist without the body.

From this definition, he goes on to differentiate between 5 powers of the soul. “The nutritive, the appetitive, the sensory, the locomotive, and the power of thinking.” From this, he differentiates between three classes of souls. Plants, he thinks, have the nutritive power. Sensory and appetitive go together, because you can’t have a desire (appetite) without sensing an object. All animals possess these two powers, but some have the additional power of locomotion. And so the second class of soul is the sensitive or animal soul. The third class has all of the above powers, but they also have the additional powers of rationality. And so these have the rational soul. 

Throughout the rest of Book 2, he outlines the nutritive and the sensitive souls. We’ll start with the nutritive and reproductive soul. The nutritive power is that which gives a thing the capability of life. By taking in resources, we are able to incorporate those resources into our own life and being. Those resources truly become a part of us. The reproductive aspect is what allows things to pass their being down to future generations. It is a small participation in the eternal and the divine. 

The Sensitive Soul is that which can use the 5 senses (sight, hearing, smell, touch and taste) in order to better act in its environment. He spends a chapter on each power. Each power has a medium through which the object must be perceived through. For example, for sight, we require light to be able to see things. All of the senses also have a proper object. For example, the sense of smell seeks “the odorous and the inodorous.” It is rather remarkable, Aristotle points out, that we can take objects from the external world and reformulate it into our minds. We can grasp the form of the thing, and recreate it in our minds, without the matter. This is what separates animals from plants. 

Finally, the rational soul is able to know the objects which are brought about through sense perception. This can be done perfectly or imperfectly. We are also able to, with this power, unite different concepts and ideas together based on similarities and differences. Oddly enough, we are also able to conduct the very power that we are using, when we think about thought. This knowledge, and knowledge like it is speculative.

As we have seen, Aristotle thinks that the soul is what animates, or makes the body to be alive in accord with the thing it is. A corpse and a man are different from each other because of the presence of the soul. He thinks there are 5 different powers of the soul that increase in complexity. He also argued that there are three types of souls: the nutritive, the sensitive, and the rational. 

Descartes Description of the Soul

It is important to start by saying that the goal of Descartes in his Meditations on First Philosophy is to prove God’s existence and the Human Soul is distinct from the body. His methodology is to be skeptical about everything that he possibly can, so that skeptics will be converted to belief in God’s existence and in the soul. His project is really an experiment to see if he can prove God and the soul with intellect alone. 

He begins by comparing the body and the soul. The body is made up of these parts which are rather indistinguishable from a corpse. The soul is that which powers the body and engages in sensation and thought. He says that the soul is “something thin and filmy-like a wind or fire or ether-permeating my more solid parts.” However, most of these powers, when starting with pure skepticism can be rejected. The body can be illusory. And the parts of the soul that are related to the body (movement and sensation) would also therefore be illusory. The one certainty that can’t be an illusion is the rational perception of one’s existence. The cogito: “I am, I exist.” From this he goes on to define himself as a thinking thing that is capable of doubt, understanding, affirmation, denial, desires, and also imagination and sensation. He concludes Meditation 2 with the realization that his mind is very capable of being wrong and that we can begin with intellect alone in our pursuit of knowledge of God and the Soul, if we are to be certain. Because of this, he thinks that the mind or soul is more trustable than the body (which was his initial intuition). 

In his 3rd Meditation he gives an argument from God’s existence and proves that he is good. From this, he can go on in Meditation 4 to the knowledge that God cannot deceive him, that God gave him judgement, and therefore that he can also trust his judgement. Now, this judgement can be incorrect, but it cannot be outright deceived. The test, for Descartes, as to whether knowledge is genuine or not, is whether the knowledge is clear and distinct. Since he can clearly and distinctly perceive material things, the material world must exist, and so sense knowledge can be trusted. 

Next, he argues that the mind and body are really distinct. The mind is indivisible, whereas the body is divisible. Only one part of the mind immediately interacts with the brain, whereas the rest of the body interacts in a more distant and confused way. This is why thought that is detached from all sense knowledge is more trustworthy than thought that relies on sense knowledge, even though this can be trusted if clear and distinct. 

And so, we could summarize by saying that for Descartes the soul is the most real part of man. The soul is where man does his thinking. Thought that is clear and distinct is most truly conformed to reality. Although sense knowledge is trustable (if clearly and distinctly perceived), knowledge that is received through pure reason has a stronger basis. The lower parts of the soul (movement and sensation) are more bodily centered and are therefore distantly related to the soul. 

Compare

I think that we can compare Descartes and Aristotle’s notions of the soul in 3 ways. First, both appreciate the fact that the soul and body are in some way related to each other. Secondly, both think that there are particular powers of the soul which can be immortal. Thirdly, both break down the soul into higher and lower parts, with rationality being higher and sensation being lower. We will discuss each of these in more detail. 

The first comparison is that both thinkers recognize a relationship between the soul and the body. Aristotle held that the majority of the soul's powers rely on the material body in some way. Even the highest power of rationality recreates and uses things perceived materially to conduct rational inquiry. Descartes also thought that, although distinct from each other, the mind and body are related to each other, distantly. The sensitive and locomotive aspects of living things are not conducted wholly by the body, but require an immaterial element, a soul, to coordinate them. 

The second comparison is that both Aristotle and Descartes think that some elements of the soul can be immortal. Aristotle, who is committed to a tight relationship between soul and body, is unwilling to admit that no parts of the soul can exist without the body. He says that “some [powers] may be separable because they are not the actualities of the body at all (6-7).” He doesn’t address this in this work, but I think here he means the ability to grasp universals, among other abilities. Although the Meditations lack any explicit reference to the immortality of the soul, I think it's reasonable to conclude from his hard division between mind and body that the mind is not affected by the death of the body. He certainly believes this by faith, even if he doesn’t demonstrate it by reason here.

The third comparison is that both break the soul down into higher and lower parts. Aristotle lists the 5 powers as nutritive, appetitive, sensitive, locomotive, and rational. Descartes puts sensation and locomotion as parts of the soul that are connected with the body, whereas rationality is unique to the soul alone. He interestingly places the appetitive power within rationality, along with the will as indistinguishable from the power of intellect. 

Contrast

To contrast, there is one fundamental difference between the two thinkers. They differ profoundly in how the soul relates to the body. Aristotle describes the soul as intimately connected with the body. The soul animates the body in such a way that without a soul, there is only a corpse left behind. The soul is so connected with the body for Aristotle that all of the bodily processes we tend to think of in biology (metabolism, homeostasis, reproduction, movement and thought) all derive themselves from the powers of the soul. The ability for us to take in food and to convert it into usable energy for our own fuel is nothing less than the soul exercising its power of nutrition in and through the body. And so the two parts of a human being, body and soul, are not opposites that work to dominate over the other, but rather partners cooperating towards the good of the whole. Man is a composite of body and soul, which are utterly united. 

 Descartes, on the other hand, conceives of the soul (or mind) as largely disconnected and separate from the body. In the opening Meditations, he admits of very Aristotiliean notions of the soul. He describes the soul in three different categories, “ate and drank, moved about, and that I engaged in sense-perception and thinking.” However, as we move throughout the Meditations he seems to want to cut off the lower powers (eating and moving) from the higher powers (intellect and will). These powers are disconnected from the body except through perhaps one part of the brain. So profound is this difference that part of the title reads “the distinction between the human soul and body.” He describes how because the mind is not made up of parts, it must be distinct from the body which is made up of parts. 

Further points could be added in contrasting these two thinkers. For example, Descartes describes the soul as not made of parts. Aristotle conceives of the soul of having different powers which constitute different parts. Be that as it may, the fundamental difference is most important: that Aristotle sees the body and soul as intimately united in the being, whereas Descartes thinks that the mind is radically distinct from the body. 

Implications

Since this is an Anthropology course, I think it would be helpful to look at the implications of these two perspectives of the soul on anthropology. I will describe three implications to anthropology. First, the role of the body. Second, the role of the mind, or how we come to know. Third, our final end. 

These two theories have very different perspectives on what role the body has in life. For Aristotle, the body is just as much a part of your being as the mind is. He conceives of man as the rational animal. As an animal, we have bodily needs which need to be met in order to thrive. As humans we need to take care of our bodies with a healthy and regimented life that integrates diet, exercise and other bodily cares that work towards the good of the whole person. 

For Aristotle, man is also a political animal. This means that man lives in the context of a family and community in which he seeks to contribute to the common good. As a bodily creature, we do this in a bodily way. We greet people, communicate, and act in and through our bodies. So, for Aristotle’s part, the question of what is the body to human life is like asking what is it to be soda for Coca Cola? It’s a fundamental and basic part of human existence. Without it, there is no life. 

For Descartes, on the other hand, the body is radically severed from the true self. Man is a thinking thing, in which thought is done in the intellect (in the immaterial mind). The body is a secondary part of the human being. We need to beware of what it communicates to us, lest it not be clear and distinct. Only if we are sure of the data that it gives us can we trust it. Otherwise, the body is solely a hindrance to the mind’s thought. 

The second implication relates to epistemology. For Aristotle all knowledge begins in the senses. We begin by perceiving physical objects, and then abstracting the form from said object. So, if we see a dog, we will begin by perceiving it as a being, then as an animal, then as a furry animal, then as a dog. From this, we can then use our intellect to use that conception to do a multitude of things (like write a compare and contrast paper). And so similar to the first point, Aristotle see’s the body as having a giant contribution into our knowledge (it provides the sense data by which thought is possible). 

Descartes, on the other hand, thinks that thought begins in the intellect. Knowledge that is derived purely through the intellect, like his proofs for God, or mathematical truths are the best form of knowledge. Knowledge that comes from the senses is less sure. Only if it has been cleared by the intellect as clear and distinct can it be trusted. So knowledge begins and ends in the intellect, and is highly skeptical of what can be trusted from our senses. 

A third implication of these two thinkers relates to our final end. This one, I will argue is complimentary between both philosophers. Both thinkers would argue that our final end is to contemplate God. Aristotle argues at the end of the ethics that since man is a rational animal his happiness should come through rational activity that occurs for its own sake. The highest form of contemplation is to contemplate the divine essence, which is God himself. Similarly, Descartes after giving his first proof for God’s existence says something striking: “I want to pause here and spend some time contemplating God: to reflect on his attributes and gaze with wonder and adoration on the beauty of this immense light, so far as the eye of my darkened intellect can bear it….experience tells us that this same contemplation...provides the greatest joy we can have in this life.” Despite their differences in conception of the soul, both thinkers agree that the human person is directed toward the same final end: to contemplate God. 

Conclusion

In this paper, we have compared and contrasted the thought of Aristotle and Descartes in regard to the soul. First, both thinkers' perspectives on the subject were outlined. Next, Aristotle and Descartes were compared to each other by three similarities: that the body and soul are related, that the soul is immortal, and that the human person is divided into parts. Then, they were contrasted in one fundamental way; namely, that Aristotle conceives as the body and soul as unified, whereas Descartes thinks they are separate. Finally, the implications of their perspectives on the soul on anthropology were reflected upon. These implications were threefold. First, that Aristotle gives a higher view of the body than Descartes. Secondly, Aristotle incorporates the bodily senses more into human knowledge than Descartes does. Third, that both thinkers believe that the ultimate purpose in life is to contemplate God and his attributes.