Aristotle’s On The Soul (or “De Anima” as the Latins transcribed it) addresses the question of what it means to be alive. It explores the self-organization of all natural and living things, from the perspective and perception of an observer. The text is a qualified addendum to the Physics, and its corollary is a short treatise called On Memory and Recollection, part of the eight short works known as Parva Naturalia, brief writings pertaining to nature.
At first glance to the unsophisticated mind, we may look around the world and recognize a part of ourselves in nature. Living things are born, grow, reproduce, and die. How is it that our perception and our senses allow us to understand these things, by nature, things like the difference between a human being and a dog? Even if we see a human being with no arms, legs, or hair, we still have the capacity to understand that the creature we are beholding is still a human being, and not a separate species. This is the central question of eidos, which Socrates is always raising questions about in the Platonic dialogues. Observing nature, and the nature of living things, reminds us that we have souls. Or, perhaps, that we are souls. But the ontological questions are best addressed in Aristotle’s Metaphysics.
The word Aristotle uses for soul is “psuche” or “psyche.” Much can be said about this word, but in essence it refers to a creature observing nature with intellect, and observing its changes and sameness while also being-at-work and staying-itself and, at the same time, open to potentia, or to becoming (see the anecdote in the preceding paragraph regarding observing nature). Nature, to Aristotle, is living, organic, and it is also ordered. It has a certain logos to it. In essence, Aristotle seeks to examine the potency that perceives the world (i.e. the perceiver perceiving his own perception and its consequences).
In contrast to Descartes, Aristotle suggests (in Book I) that it would be unwise to merely trust things that are immediately “clear and distinct” to our senses, because the senses are deceptive. Instead, we should proceed from what is familiar. The moderns, following from Descartes, are doubters that knowledge can ever be attained because proceeding from common opinions is suspect to the modern mind. Most notably in his Meditations on First Philosophy, Descartes sits alone in a room and he fabricates an imagined world for himself, that is perfectly knowable, and that somehow corresponds to the world we live in, as well. This is attained through instruments and mathematical precision, not through the facticity of human awareness. Thus, geometry comes to prominence in Descartes’s writings. Nevertheless, the central epistemological problem persists in Descartes. In other words, what is the thinking and perceiving thing that is Descartes? He seems to suggest his own perceiving mind and God are the only two things he can be sure of. The human element is minimized with the moderns. They seek to find the superior, more democratically approved theory, in order to posit a world picture (excluding souls), not to explore the world as a soul perceiving other souls and natural phenomena.
In contrast, Aristotle suggests that self-discovery comes not from solitary self-examination of the senses, but rather from experience and observations of living things. At least Aristotle acknowledges the possibility of human experience. While Platonic dialogues frequently (and exoterically) ask the question ti esti or “what is it” in attaching universal names to particular things, but Aristotle is interested in how the world sorts itself out. Living things are being, and insofar as they are living, they are beings at work. And Aristotle is also concerned with what keeps these beings in order amidst nature at all. Thus, he looks for beings-at-work-staying-themselves.
Plato, in his Timaeus, offers a pleasurable myth that seriously addresses deep questions in a playful manner, rather than a rational examination of the cosmos. Elsewhere in the Phaedrus, Socrates tells Phaedrus that he much prefers myth-making and story-telling, rather than more sober and rational criticisms, because self-knowledge is better attained through myth-making.
In Aristotle’s On The Soul, he proceeds from commonly held assumptions, upward toward a glimpse at truth, or at least a deeper understanding of the nature of things. He begins with the commonly held belief that knowledge is “something beautiful and honored” (Book I, 402a), and begins an inquiry into the soul, since the soul “is in some way the governing source of all things.” He runs through various impasses when defining the thinghood of the soul -Democritus, Pythagoras, and even Plato in his Timaeus. All these thinkers define soul by three things: motion, sense perception, and bodiliness (405b 12).
In Book II, we get Aristotle’s definition of the soul (summarized here by Joe Sachs): “The body (soma) is material for the soul (psyche or psuche) which is its invisible look (eidos) because the body has being as a potency for the being-at-work-staying-itself. The body’s thinghood that keeps it being a body at all by means of speech, is its soul. The soul constantly maintains the body as a kind of living thing that remains in its self-same category, and the soul is nutritive, as it transforms material from the natural world into perceptible and necessary ingredients to sustain the soul.” Book II, discusses explores the varying powers of the soul, such as the nutritive, reproductive, perceptive potential and so on. The final section of On The Soul is Book III which explores several of the most important ways the soul thinks. Only now, do we see Aristotle using “clarity” and “distinctness” to explore what comes to light with greater certainty.
The past two thousand years have brought considerable criticisms of Aristotle’s notion of “soul,” though most have originated in the last two hundred years in the modern era. Typical criticisms have attempted to push Aristotle’s definition into one of two camps: pure materialism, or else Aristotle is some manner of neo-Christian “ghost in the machine” dualist (i.e. a soul-body distinction is made, which, of course, is never explicated in Aristotle’s On The Soul. He does provide one artless metaphor wherein the soul is like the captain of a ship, but this should not be taken too heavily).
For these readings I used the magnificent Joe Sachs translation of Aristotles On The Soul.