Summary: On the Soul
On the Soul is a treatise by Aristotle that represents one of the earliest works on psychology and the theory of knowledge.
What is the soul? Is it immortal? What is its relationship with the body?
Aristotle begins by critically exposing the theories of his predecessors, from the pre-Socratics to Plato, and then proposes his own conceptions.
Other works: Physics Metaphysics Nicomachean Ethics Poetics
Book I
All knowledge is admirable, but there is knowledge superior to other knowledge, either because of its accuracy
, or because it deals with objects of greater value and more worthy of admiration
1.
For these two reasons, the study of the soul occupies a high place in the hierarchy of the sciences.
Moreover, the truths discovered in such a study are useful for the science of nature, since the soul is in short the principle of animals
2. Psychology is a branch of physics.
The aim of the work is to know the nature and properties of the soul.
How is the soul to be characterized ontologically? Is it a substance, a quality, a quantity, or yet another category? Is it in potency or in entelechy? Divisible or indivisible, without parts? Can we say that the soul of the horse is the same as that of man, or does each species have a different kind of soul?
Is the soul immortal? Aristotle offers an argument to begin to answer the question: if the soul has a function of its own, and remains independent of the body, then it is immortal. If this is not the case, then the soul cannot subsist independently of the body.
Thought is the operation which seems proper to man; but if this is merely a species of imagination, it is irremediably bound to the body, for imagination presupposes sensation and consequently the body.
All the affections of the soul (what it undergoes) are given with a body
3. Aristotle takes the example of courage or gentleness. If this is so, then affections are forms committed to matter
and the study of the soul falls to the physicist
4.
We may then explain psychological phenomena as a dialectician or as a physicist, depending on whether we take into consideration the form or the matter of the affection under consideration. The dialectician will explain anger by the desire to return the offence, for example, while the physicist will say that it is a boiling of the blood that surrounds the heart.
If there are properties of the soul that depend neither on the body nor on matter, they are the object of study of the metaphysician.
Aristotle, as is his wont, found for example in The Physics, begins by recalling the history of the doctrines on the soul formulated by his predecessors (the pre-Socratics and Plato).
Most seem to agree on one point: the soul is animate. Now the animate differs from the inanimate in two characteristics: movement and sensation.
Movement indeed seems to belong to the soul in the opinion of these philosophers, and many (Democritus, Leucippus, certain Pythagoreans, Anaxagoras) say that the soul is par excellence and primordially the mover
5. The soul moves things, first and foremost the body, and moves itself, which is why Democritus likened it to a kind of fire or heat
6, while Anaxagoras maintained that intelligence imparted motion to the universe
7.
Xenocrates for his part defined it as a number that moves itself
8, while Heraclitus asserted that it is because the soul is movement that it can know things, which are in a perpetual flux (the moved is known by the moved).
However, this unanimity does not prevent Aristotle from criticising this theory. He absolutely refuses that movement can belong to the soul. For him the animal breaks down into a mobile, the body, and a motor, the soul, which is immobile.
Aristotle here expounds theories developed in another work, The Physics.
First of all, the motor is not necessarily itself moved: let us recall his famous definition of the agent intellect -which created the world- as a motionless motor.
Next, any mover can move by itself, or by something else (in other words, by accident, like sailors who move at the same time as their ship).
Finally, he recalls the four species of motion identified in The Physics: translation, alteration, diminution and increase.
None of these movements can belong to the soul. Indeed, each of these types of movement occurs in a place, so if the soul is moved, this would mean that it is in a place, which for Aristotle seems impossible.
1 On the Soul, I,1, 402a
2 ibid.
3 ibid., 403a
4 ibid.
5 I,2, 403b
6 ibid., 404a
7 ibid., 405a
8 ibid., 404b