Key Arguments

• He asserts: 'The soul of the living body is its cause and starting-point', and immediately notes that 'things are said to be these in many ways', introducing his doctrine of several senses of 'cause' and 'starting-point'.
• He explicitly enumerates the three causal roles: 'the soul is likewise a cause in three of the ways distinguished. 188 For the soul is a cause as that from which the movement comes, as that-for-the-sake-of-which, | 415 b 10 | and as the substance of animate bodies.'
• He justifies the substantial/formal role by appealing to his general metaphysics: 'For the cause of its being for everything is its substance; living is the being for living things; and the soul is cause and starting-point of this. Further, the actuality is the account of what is potentially.' So soul, as actuality and defining account of a living thing, is its substantial cause.
• He argues for the final-cause role: 'It is evident that the soul is also cause as that-for-the-sake-of-which. | 415 b 15 | For just as the understanding does things for the sake of something, in the same way so does nature, and this is its end. And the soul is naturally such in animals.'
• He implies the efficient-cause role by stating that 'a soul is also that from which movement with respect to place first derives—although not all living things have this capacity', and earlier counted 'that from which the movement comes' among the ways it is cause.

Source Quotes

And what persists is not the thing itself but something like itself, not one in number but one in form. The soul of the living body is its cause and starting-point. But things are said to be these in many ways, and the soul is likewise a cause in three of the ways distinguished.

The soul of the living body is its cause and starting-point. But things are said to be these in many ways, and the soul is likewise a cause in three of the ways distinguished. 188 For the soul is a cause as that from which the movement comes, as that-for-the-sake-of-which, | 415 b 10 | and as the substance of animate bodies. 189 That it is so as substance is clear.

189 That it is so as substance is clear. For the cause of its being for everything is its substance; living is the being for living things; and the soul is cause and starting-point of this. Further, the actuality is the account of what is potentially.

For the cause of its being for everything is its substance; living is the being for living things; and the soul is cause and starting-point of this. Further, the actuality is the account of what is potentially. 190 It is evident that the soul is also cause as that-for-the-sake-of-which. | 415 b 15 | For just as the understanding does things for the sake of something, in the same way so does nature, and this is its end.

Further, the actuality is the account of what is potentially. 190 It is evident that the soul is also cause as that-for-the-sake-of-which. | 415 b 15 | For just as the understanding does things for the sake of something, in the same way so does nature, and this is its end. And the soul is naturally such in animals.

Key Concepts

• The soul of the living body is its cause and starting-point.
• the soul is likewise a cause in three of the ways distinguished. 188 For the soul is a cause as that from which the movement comes, as that-for-the-sake-of-which, | 415 b 10 | and as the substance of animate bodies.
• For the cause of its being for everything is its substance; living is the being for living things; and the soul is cause and starting-point of this.
• Further, the actuality is the account of what is potentially.
• It is evident that the soul is also cause as that-for-the-sake-of-which. | 415 b 15 | For just as the understanding does things for the sake of something, in the same way so does nature, and this is its end.

Context

Middle of II.4 (415b7–18, 415b20–22), where Aristotle applies his four-causes framework to the soul, identifying it as the formal, final, and efficient cause of living bodies and tying this to his earlier hylomorphic account of soul as actuality.