On the Soul

“In general, and in all ways, it is one of the hardest things to gain any conviction about the soul.” 

Aristotle’s conviction about the difficulty of the subject matter is borne out in the text itself, which is at times highly abstract, challenging to follow, disjointed, and fragmentary. In putting this statement at the beginning of the work, however, Aristotle prepares us for these difficulties.

“[S]oul is that by which primarily we live and perceive and think.”

This is one of several pithy statements in the book about the nature of the soul. This one binds together the three main functions of the soul: biological life, the operation of the senses, and the operation of intellect—the latter implies that the statement is made specifically from the point of view of human life.

“But perhaps it is necessary first to distinguish in which of the kinds it is and what it is, that is to say whether it is a particular and substance, or a quantity or quality or some other of the categories that we have distinguished, and again whether it is one of the things that are in potentiality or rather some actuality.” 

Aristotle’s methodical approach to philosophy includes placing phenomena in various categories of being, some of which he lists here: particulars, substance, quantity, quality. A substance is something that exists independently, while quality and quantity are things that inhere in something else. Categorizing things in this way helps us understand their nature and how they function.

“[T]he affections of the soul, insofar at least as they are such things as anger and fear, are in this way inseparable from the natural matter of living things […].”

Aristotle declares that emotions depend on the body for their function; for example, anger manifests in increased heat in the body. Throughout the book he emphasizes that the soul and body are inextricably connected.

“Now in our investigation of the soul, if we are in doubt about those things of which we should gain clear knowledge as we proceed, it is necessary that we collate the opinions of as many of our predecessors as have given a view about the soul with the aim of adopting all sensible proposals and of guarding against anything that may have been not so sensibly suggested.” 

This quote shows Aristotle’s predilection for building upon, and at times critiquing, the opinions of previous philosophers as a prelude to expounding his own views. This is part of his methodical ordering of his philosophical discourse.

“Perhaps indeed it would be better not to say that the soul pities or learns or thinks but that the man does in virtue of the soul.”

Aristotle considers the question of whether the soul itself moves or, rather, produces movement in the body. He concludes that the soul does not itself move but rather instigates movements in the body, since, for example, emotions like anger or fear happen in particular parts of the body or soul and not in the soul as a whole.

“Thought and contemplation are indeed diminished when some other internal part decays, but in themselves they are unaffected.”

Aristotle is convinced that the decay we undergo as we age affects only the body and not the soul because the operation of the senses depends on the condition of the sense organs. Aristotle concludes, “This leaves open the possibility that the mind is something more divine and unaffected” (146). In other words, the soul might be imperishable, as Plato believed.

“[F]or it is very reasonable to suppose that [the soul] is the most primitive and effective thing by its nature, despite the view that the elements are the primary things that exist.” 

Aristotle goes against the view that the soul is made up of all the physical elements. For Aristotle, the soul, and not the elements, is the primary thing that exists; thus, it cannot be made up of other previously existing things.

“Now the soul comprises cognition, perception and belief-states. It also comprises appetite, wishing and the desire-states in general.”

This is another helpful sentence that sums up the activities of the soul. Aristotle specifies that in addition to biological life, perception, and thought, the soul also includes wishing and desiring—the appetitive faculties. He later explains that desire and appetite play a role in producing movement in the animal soul.

“Now matter is potentiality, and form is actuality […].” 

The distinction between potentiality and actuality is an important concept in Aristotle’s philosophy. Aristotle says that matter is potential until it is actualized by a specific form, which determines what the thing is. Thus, in a chair, the matter is the wood and the form is the shape and design that make it a chair.

“If then we must say something in general about all types of soul, it would be the first actuality of a natural body with organs.” 

Aristotle applies the doctrines of form-matter and potentiality-actuality to the body-and-soul complex. Body is matter, and soul is the principle that makes the body alive and a specific thing. Organs are the various parts that help an organism function, whether plant or animal.

“We should not then inquire whether the soul and body are one thing, any more than whether the wax and its imprint are […].”

This analogy illustrates Aristotle’s belief about the essential unity of the body and the soul. They work in tandem and as a single entity, like an imprint on wax (used to seal papers). Aristotle goes on to imply that if the soul were to leave the body, the body would no longer be a body except as a figure of speech.

“For if an eye was an animal, then sight would be its soul, being the substance of the eye that is in accordance with the account of it.” 

This analogy implies that the soul is what makes a thing what it is; the soul defines a thing’s essence and function. Just as sight is the essence of an eye, the soul is the essence of a body. A body without a soul is simply a dead body. Thus, Aristotle can say that “soul and body are the animal” (158).

“For our definitional account should not only show what it is, as the majority of definitions do, but must also contain the reason for its being as it is, which must shine through it.” 

This is a notable statement about the nature of philosophical explanations and definitions. As Aristotle sees it, a definition should go beyond merely defining what a thing is to also show its reason for being that way. By building on propositions that are relatively obvious, we reach more complex and clearer definitions. Thus, we gain knowledge in a progressive manner. In On the Soul Aristotle hopes to go beyond saying that the soul is what makes a living thing alive to explain how it does this.

“[T]he soul is a kind of actuality and account of that which has the potentiality to be of the appropriate kind.” 

Aristotle stresses that souls are united to bodies to which they are appropriately fitted; they are not combined with bodies in a random or haphazard way. Each matter thus has its appropriate form. This is an instance of the kind of philosophical method implied in the previous quote: Aristotle is trying to go beyond the most obvious statements about the soul and the body to define the particular nature of the union and the kind of body required.

“The soul, then, is the cause and principle of the living body […].” 

Central to Aristotle’s philosophy is finding the causes for things; for him, the cause is the explanation for why a thing exists and why it is what it is. He sees the soul in relation to the body as its cause. “Principle” implies that the soul is prior to the body, as the thing that gives it life and existence.

“[T]he soul is the reason for the body as that for which it is […].” 

This excerpt restates the idea of the previous quote with a special nuance, that the soul is the body’s reason for being. In Aristotle’s terms, the soul is the final cause of the body—the purpose for which it exists.

“[W]e do not have [the sense of smell] in an accurate way but worse than many animals.” 

In Aristotle’s discussion of the individual senses and how they work, he observes that other animals have a keener sense of smell than humans do. This is biological observation is typical of Aristotle, who was a pioneer in zoology.

“[T]he sense is the recipient of the perceived forms without their matter, as the wax takes the sign from the ring without the iron and gold […].”

Aristotle refines his theory of sense perception by applying his form-matter theory to it. When we perceive things, we perceive their form—their essential nature—but do not literally take in their matter. This builds on the previously stated idea that perception is a kind of change that takes place in the animal.

“So sensation is a formula, dissolved or destroyed by excesses.” 

Aristotle sees each of the senses as a formula, ratio, or concord between the sense and the object perceived. Thus, if the object hits the sense too strongly or in excess (e.g., a noise that is too loud), its equilibrium will be destroyed and the animal may be hurt.

“Thinking, then, is something other than perceiving, and its two kinds are held to be imagination and supposition.” 

Perceiving and thinking are different things, and one reason why we know this is that only human beings can think, while all animals can perceive. Imagination is the forming of images in the mind from things we have perceived in the world. By “supposition” Aristotle means a state of belief about things.

“[T]he soul is in a way all the things that exist.” 

Aristotle states the idea, perhaps somewhat curious to us today, that in perceiving or thinking we “become” the thing that we perceive or think about. In other words, our soul is capable of having a rapport with any object in the world around us. This is based on the pre-Aristotelian idea that like perceives like. To perceive things, our soul has to be in some sense like those things.

“The soul, then, of animals is defined according to two capacities, that of discernment, which is the function of thinking and perceiving, and that of producing locomotion.” 

This quote provides yet another definition of what the soul does, though it introduces the further distinction that the soul both discerns things (i.e., perceives or thinks about them) and produces physical movement.