De Anima by Aristotle

My rating: 5 of 5 stars

As I have lately been making my way through Aristotle’s physical treatises, I have often observed that many of Aristotle’s errors stem from his tendency to see the physical world as analogous to a biological organism. So it is a pleasure to finally see Aristotle back on his home territory—living things. While Aristotle’s work in proto-physics and proto-chemistry is interesting mainly from a historical perspective, this work is interesting in its own right; in just a hundred pages, Aristotle manages to assemble a treatise on the fundamentals of life.

The first thing the modern student will notice is that Aristotle means something quite different by ‘soul’ than how we normally understand the word. The word ‘soul’ has come to mean an immaterial, specter-like wraith, the spiritual core of one’s personality—trapped, only temporarily, in a body; and this view has, over the years, caused problems for philosophers and theologians alike, for it remains to be explained how an immaterial spirit could move a material body, or how a material body could trap an immaterial spirit. Aristotle avoids these awkward questions. What he means is quite different.

Aristotle begins by observing that all forms of behavior, human or animal, require a body. Even supposedly ‘mental’ states, such as anger, love, and desire, all have concomitant physical manifestations: an angry man gets red in the face, a man in love stares at his beloved, and a man who desires alcohol tries to get it. From this, Aristotle quickly concludes that all the Pythagorean and Platonic talk of the transmigration of souls is silly; a soul needs a body, just as a body needs a soul. Furthermore, a specific soul doesn’t need just any body, but it needs its specific body. Soul and body are, in other words, codependent and inseparable. In Aristotle’s words, “each art must use its tools, each soul its body.”

This still leaves the question unanswered, what is a soul? Aristotle answers that the soul is the form of the body. Alright, what does that mean? Keep this in mind: when Aristotle says ‘form’, he is not merely talking about the geometrical shape of the object, but means something far more general: the form, or essence, of something is that by which it is what it is. Here’s an example: the form of a bowl is that which makes a bowl a bowl, as opposed to something else like, say, a plate or a cup. In this particular case, the form would seem to be the mere shape of the object; isn’t the thing that makes a bowl a bowl its shape? But consider that there is no such thing as a disembodied bowl; for a bowl to be a bowl, it must have a certain shape, be within a certain size range, and be embodied in a suitable material. All of these qualifications, the shape, size, and material, Aristotle would include in the ‘form’ of an object.

So the soul of living things is the quality (or qualities) that differentiate them from nonliving things. Now, the main difference between animate and inanimate objects is that animate objects possess capacities; therefore, the more capacities a living thing has, the more souls we must posit. This sounds funny, but it’s just a way of speaking. Plants, for Aristotle, are the simplest forms of living beings; they only possess the ‘vegetative soul’, which is what makes them grow and develop. Animals possess additional souls, such as that which allows them to sense, to desire, to imagine, and—in the case of humans—to think. The ‘soul’, then, is a particular type of form; it is a form which gives its recipient a certain type of capability. Plants are only capable of growth; animals are capable of growing, of moving, and of many other things.

Aristotle sums up his view in a memorable phrase: “From all this it is obvious that the affections of soul are enmattered formulable essences.” These capacities cannot be ‘enmattered’ in just anything, but must be embodied in suitable materials; plants are not made of just anything, but their capacities for growth always manifest themselves in the same types of material. Aristotle sums up this point with another memorable phrase: “soul is an actuality or formulable essence of something that possesses the potentiality of being besouled.”

So an oak tree is made of material with the potentiality of being ‘besouled’, i.e., turned into a living, growing oak tree. Conversely, a life-sized statue of an oak tree made of bronze would still not be an oak tree, even if it shared several aspects of its form with a real oak tree. It isn’t made of the right material, and thus cannot possess the vegetative soul.

I have given a somewhat laborious summary of this because I think it is a very attractive way of looking at living things. It avoids all talk of ‘ghosts in the machine’, and concentrates on what is observable. (I should note, however, that Aristotle thought that ‘mind’, which is the faculty of reason, is immaterial and immortal. Nobody’s perfect.)

I also find Aristotle metaphysical views attractive. True to his doctrine of the golden mean, he places equal emphasis on matter and form. He occupies an interesting middle-ground between the idealism of Plato and the materialism of Democritus. In order for a particular thing to be what it is, it must both have a certain form—which is embodied in, but not reducible to, its matter—and be made of the ‘right’ types of matter. Unlike Plato’s ideals, which reside in a different sphere of reality, existing as perfect essences devoid of matter, Aristotle’s forms are inherent in their objects, and thus are neither immaterial nor simply the matter itself

The treatise ceases to be as interesting as it progresses, but there are a few gems along the way. He moves on to an investigation of the five senses, and, while discussing sight, has a few things to say about light. Aristotle defines light as the quality by which something transparent is transparent; in other words, light is the thing that can be seen through transparent things. I suppose that’s a respectable operational definition. Aristotle also considers the idea that light travels absurd; nothing could go that fast:

Empedocles (and with him all others who used the same forms of expression) was wrong in speaking of light as ‘traveling’ or being at a given moment between the earth and its envelope, its movement being unobservable by us; that view is contrary both to the clear evidence of argument and to the observed facts; if the distance traversed were short, the movement might have been unobservable, but where the distance is from extreme East to extreme West, the draught upon our powers of belief is too great.

Aristotle also has a few interesting things to say about sense:

By a ‘sense’ is meant what has the power of receiving into itself the sensible forms of things without the matter. This must be conceived of as taking place in the way in which a piece of wax takes on the impress of a signet-ring without the iron or gold; we say that what produces the impression is a signet of bronze or gold, but its particular metallic constitution makes no difference: in a similar way the sense is affected by what is colored or flavored or sounding, but it is indifferent what in each case the substance is; what alone matters is what quality is has, i.e. in what ratio its constituents are combined.

So we don’t take in the matter of a bowl through our eyes, but only its form. All of our senses, then, are adapted for observing different aspects of the forms of objects. Thus, Aristotle concludes, all knowledge consists of forms; when we learn about the world, we are mentally reproducing the form of the world in our minds. As he says: “It follows that the soul is analogous to the hand; for as the hand is a tool of tools [i.e. the tool by which we use tools], so the mind is the form of forms [i.e. the form by which we apprehend forms].” (Notice how deftly Aristotle wields his division of everything into matter and form; he uses it to define souls, to define senses, and then to define knowledge. It is characteristic of him to make so much headway with such seemingly simple divisions.)

For a long time, I was perplexed that Aristotle was so influential. I was originally repulsed by his way of thinking, put off by his manner of viewing the world. His works struck me as alternately pedantic, wrongheaded, or obvious. How could he have exerted such a tremendous influence over the Western mind? Now, after reading through much more Aristotle, this is no longer perplexing to me; in fact, I often find myself thinking along his lines, viewing the world through his eyes. It takes, I believe, a lot of exposure in order to really develop a sympathy for Aristotle’s thought; but with its emphasis on balance, on growth, on potentiality, it succeeds in being a very aesthetically compelling (if often incorrect) way of viewing things.

This piece represents, to me, Aristotle at his best. It is a grand synthesis of philosophy and biology, probably not matched until William James’s psychological work. Unlike many gentlemanly philosophers who shut themselves in their studies, trying to explain human behavior purely through introspection, Aristotle’s biologically rooted way of seeing things combines careful observation—of humans and nonhumans alike—with philosophical speculation. It is a shame that only the logic-chopping side of Aristotle was embraced by the medievals, and not his empirical outlook.

View all my reviews