Aristotle’s De Anima Book I

By Jon|January 10, 2017|Aristotle, Authors, My PhD Comprehensive Exam Experiment, On the Soul (De Anima) of Aristotle, Titles of Works|

Chapter 1 – The Plan of Study of the Soul

Sentence: Since activities and powers of soul (form) appear to always involve the body (matter), and since the natural philosopher studies form in matter (properties), the natural philosopher should study the soul insofar as it pertains to the body (properties moving back to their cause).

In this chapter, Aristotle gives us some idea of the dignity, plan and difficulty in studying the soul. It is dignified because of its object (even though accuracy can dignify a science too). We must discover the soul’s nature, essence and properties. Some of those properties will be essential and pertain to the definition. Is it at quantum, quale or substance? By understanding definition, we can understand properties and by noting our experience of properties, we improve our definitions. Since antecedent and consequent passions follow change in the body, and since change in the soul always affects the body, the body must enter into the definition of the soul as its matter. While we can define passions, for example, only by their material principle, or only by their formal principle, a complete definition gives these two and the final cause (like a shelter built against destruction from bricks). This is what the natural philosopher should do in defining the soul and its parts, and leave properties which are separable by the artist to the him, separable from matter to the mathematician and perhaps to the first philosopher. But first we must consider the opinions of ancients for counsel and the point out the errors.

More details:

  • Sciences can be importance because of their accuracy or because of their object. We want to know the nature and essence and properties of the soul. This is difficult because demonstrations require a common method, but the soul might not admit of a common method because of unique souls, and because there are uncertain starting points. We need to find the soul’s genera, its divisibility, specific difference, and parts, and if parts its objects. Define the powers before the acts or acts before powers?
  • Definitions (often from dialectic) help us understand properties, but also the properties help us understand the definitions because we can check out definitions against experience. Definition without accidental qualities is not a real definition.
  • Does the soul share these properties with the body? It’s not an easy question, but it seems most cases the soul is affected by or affects the body, but there is no case of it acting that doesn’t involve a body. Emotions like anger seem not to happen without the body being affected, so therefore they must have something to do with the body.
  • Thinking would seem to be the most likely exception, but even it requires imagination which pertains to the body. But evidence that the passions are tied to the body is found in their being consequently or antecedently provoked by the physical state of the body. This is evidence that passions relate to material and should not be defined apart from material. (the bodily organ or power of the body is material, proceeding from is agent and existing for is final.
  • If there are properties that are particular to the soul, then they could be separated from the body. If not, then it won’t be. Since definitions must include matter and form, and since dispositions and activities presume a substrate, then definitions of dispositions presume a material substrate. Everything material falls in natural science and since this includes the powers and substrate, it is the task of the physicist to study the soul inasfar as it is joined to the bdoy (maybe the intellect isn’t.)
  • (403a29) The physicist would define anger as boiling blood (material principle), but dialectician as the appetite for returning pain for pain (formal principle). The matter MUST be stated. So there are three definitions: formal, material, perfect: material and formal and final cause (shelter against destruction by wind rain and heat with stones bricks.)

Chapter 2 – Previous Opinions on the Soul

In taking counsel about the soul from prior writers in order to correct their errors and learn from their truths, Aristotle first creates a record of what they thought were characteristics of the soul and then a record of what they thought were its principles. The characteristics or properties agreed upon by all the ancients are sensation and movement.  Causes of movement suggested are breathing motes/fireballs from mind (Democritus), the soul itself (Anaxagoras), all of the elements (Empedocles), Plato also believed the soul was formed out of the elements (like all forms participating in them). But as to the nature and number of first principles of soul: Democritus had the best opinion that soul and mind are the same since movement came to the soul from fire and permeates the body through the breath…then there were other, not so accurate opinions, but all characterized the soul as having movement, sensation, incorporeality.

  • We will council our predecessors in order to profit from their insights and to avoid their errors.
  • To start our inquiry, we recognize that all predecessors held that movement and sensation are the characteristic marks of the soul
  • Since what doesn’t receive motion from another cannot give motion to another they believed that it simply was movement.
    • Democritus thought that this movement came to the soul from fire made of infinite hot spherical particles (like electrons) as we see coming through windows, but which never rest. Their shape is well adapted to permeate everything, and came in through the breath – also regarded as characteristic of life.  When our body runs out, the soul dies. Soul and mind are the same.
    • Pythagoreans thought similarly about the motes except they are always seen in movement.
    • Anaxagoras thought movement was the soul like Democritus but unlike him, he thought that not everything has mind – even some humans.  Everything living has soul, but not everything has mind.
    • Empedocles thought that the soul is identical with what is eminently originative of movement like the others, but he identified it with the principle(s) of nature, formed out of the elements.
    • Plato fashioned the soul out of his elements, since like is known by like and since everything is formed out of principles and elements. The divided line: mind/forms (monad/point – apprehends a unity), science (dyad because reasoning from principle to conclusion), opinion (triangle – because one principle is a starting point and one is in doubt about the conclusion), sensation (the solid – these are the objects of sensation).
  • Some combined these by accepting  both premises 1) soul is like mind, 2) soul is like movement. They said the soul is a self moving number. Fire for example, moves and is moved by itself.
  • The nature and number of the first principles
    • Democritus expressed this better by saying that mind and soul are one and the same thing and this is one of the primary and invisible bodies, and it is made up of these round particles because they are the most mobile, so it is the shape of particles of both fire and mind.
    • Anaxagoras distinguishes soul and mind but treats them as a single substance – knowing and movement were started by mind.
    • Thales thought the soul was a motive force, like magnet moves iron.
    • Diogenes thought the soul was air because air was the finest grain and first principle, having the power to originate movement.
    • Heraclitus thought warm exhalation is soul since it is incorporeal and in ceaseless flux.
    • Alcmaeon thought the soul is immortal because it resembles the immortals, and that this immortality belongs to it in virtue of ceaseless movement.
    • Hippo thought it was water, since fluid is in all living things. Critias thought it was blood since perception is most characteristic aspect of soul and they thought blood caused this.
    • All characterize the soul as having three marks: movement, sensation, incorporeality.

Chapter 3- Movement – Aristotle Shows Problems with Materialism, Dualism, and Harmony Theory

Aristotle attempts to show that movement is not the essence or even a property of soul. There are two ways a thing can be moved: indirectly like sailors on a ship, and directly like the ship – on account of itself/captain. Aristotle then asks, is the soul directly moved?

He makes six arguments for why the soul is not moved essentially, but instead is moved accidentally.

  • All change takes place in one of four categories. If it is moved essentially by other things, then it would be moved accidentally and have no need to be located anywhere in space, just like the color white or a number need not be in space. But if it were moved essentially, then it would have to move in one of the four categories and if any of of them, then they require space.
    • Aquinas thinks this argument fails because 1) Not all change has to be from place to place, it can be in a place. 2)
  • Second if the soul moves from place to place, its movement must be natural and any natural motion is susceptible to violence. But if the soul has a natural place of rest, then it is susceptible to violence at rest – which is impossible if they are supposed to be spontaneous.
  • The third…If the soul moves downward it must be earth if up fire…for the kind of movement reveals the kind of soul we can infer back to. Someone might object that an animal can be moved by approaching it. Aristotle responds that is true that it is moved, but it is moved incidentally – because it has the power to move of its own accord but that is only from the sensible organ – which doesn’t force the movement.
  • The fourth is that the soul might be moved by the same movements which move the body. But the body moves in space and so therefore the soul would also, and if thats the case it could leave the body and return, which means animals could come alive again [?!?!]
  • The fifth is that when something is of the essence of a given subject, it does not need to be explained by anything other than that subject. Then the soul would not need reference to anything outside it to explain its movement- it is essentially moving. But the soul is clearly moved by sensible things – even the intellectual part.
  • The sixth is that if it is the soul’s essence to be moving, and if every movement is going toward or away from what governs and directs it, then they say it must leave its own essence (they say), and thereby be destroyed.
    • But the problem with this argument is that it doesn’t distinguish between movement proper, and operation. Movement proper means leaving the cause of the movement, while operation my be internal.

Plato said the soul was constituted of numbers which have harmonic proportions for two reasons

  • Similarity and connaturality are always a cause of a pleasure, and since the soul takes pleasure in harmonies/displeasure in disharmony, it seems to be part of the nature of the soul (connatural).
  • They supposed the heavens had beautifully harmonious sounds, and since this was produced by the world soul, they supposed the human soul also participated in these shenannigans.

Aristotle responds to the belief that the soul is a spatial magnitude with ten arguments:



Chapter 4 – The Soul Cannot be a Harmony

A harmony, in this context, is the mixture of elements in a certain proportion to each other. But the soul cannot be this kind of harmony because there are many composite parts of those variously compounded….Of what “part” is the mind?

It is better to call the ‘good states of the body’ a harmony than to say the soul is itself a harmony.

It is also strange to call the soul a ratio of the elements because there will be many souls distributed throughout the body since there are many mixtures throughout the body (variously compounded).


Then he summarizes what has been said this far. The soul cannot be moved in any sense except accidentally, but it moves the thing which moves it (vehicle).

To say that it is the soul which is angry is the same as to say that it is the soul that weaves webs or builds houses. It is better to say that weaving is what the man does with his soul.

Sometimes the emotion terminates in the soul, other times it starts from the soul (sensation) and terminates with the movement of sense organs.

The mind on the other hand seems to be indiependent of the body and least likely to be destroyed. If it were it would be from old age, and even that is just a result of its vehicle – some other inward part – decaying, not the mind itself. The vehicle decays, memory and love cease, but they are not of the mind.

The most unreasonable view of all enumerated is that the soul is a self-moving number. How are we to imagine a unit being moved?

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