Key Arguments

• He claims that everything that is alive and has a soul, from birth to death, necessarily has growth, a prime of life, and a time of withering away, and these processes are impossible without nourishment; therefore all such things must possess the nutritive capacity.
• He infers that 'the nutritive capacity must therefore be present in all things that grow and wither away', treating growth and withering as sufficient signs of the nutritive soul.
• He denies that perception is necessarily present in all living things, because 'those things that have a body that is simple cannot have touch, and neither can those that are not receptive of the forms without the matter,' so some embodied living things cannot support perceptual reception.
• He defines animals by perception: 'Animals, though, must have perception, and without this nothing can be an animal, if nature does nothing pointlessly,' explicitly tying animality to the possession of some perceptual faculty.
• He invokes his teleological principle that 'all things that are by nature are for the sake of something or will be concomitants of those things that are for the sake of something,' and uses it to argue that any perambulatory body without perception would 'perish and fail to arrive at its end, which is the function of nature.'
• He reasons that a body capable of locomotion, if lacking perception, could not secure nourishment ('For how would it be nourished?'), and so could not survive to realize its natural end, showing that perception is necessary for self-preservation in moving organisms.

Source Quotes

III 12 The nutritive soul, then, must be possessed by everything that is alive and has a soul from its birth until its death. For what has been born must have growth, a prime of life, and a time of withering away, and these things are impossible without nourishment.

III 12 The nutritive soul, then, must be possessed by everything that is alive and has a soul from its birth until its death. For what has been born must have growth, a prime of life, and a time of withering away, and these things are impossible without nourishment. The nutritive capacity must therefore be present in | 434 a 25 | all things that grow and wither away.

For what has been born must have growth, a prime of life, and a time of withering away, and these things are impossible without nourishment. The nutritive capacity must therefore be present in | 434 a 25 | all things that grow and wither away. Perception, on the other hand, is not necessarily present in all living things, since those things that have a body that is simple cannot have touch, and neither can those that are not receptive of the forms without the matter.

The nutritive capacity must therefore be present in | 434 a 25 | all things that grow and wither away. Perception, on the other hand, is not necessarily present in all living things, since those things that have a body that is simple cannot have touch, and neither can those that are not receptive of the forms without the matter. 438 Animals, though, must have perception, | 434 a 30 | and without this nothing can be an animal, | 434 a 30a | if nature does nothing pointlessly.

Perception, on the other hand, is not necessarily present in all living things, since those things that have a body that is simple cannot have touch, and neither can those that are not receptive of the forms without the matter. 438 Animals, though, must have perception, | 434 a 30 | and without this nothing can be an animal, | 434 a 30a | if nature does nothing pointlessly. 439 For all things that are | 434 a 31 | by nature are for the sake of something or will be concomitants of those things that are for the sake of something.

438 Animals, though, must have perception, | 434 a 30 | and without this nothing can be an animal, | 434 a 30a | if nature does nothing pointlessly. 439 For all things that are | 434 a 31 | by nature are for the sake of something or will be concomitants of those things that are for the sake of something. Every body that can perambulate, then, if it did not have perception, would perish and fail to arrive at its end, which is the function of nature.

439 For all things that are | 434 a 31 | by nature are for the sake of something or will be concomitants of those things that are for the sake of something. Every body that can perambulate, then, if it did not have perception, would perish and fail to arrive at its end, which is the function of nature. 440 For how would it be nourished? | 434 b 1 | For the stationary ones this is indeed present where they have grown.

Every body that can perambulate, then, if it did not have perception, would perish and fail to arrive at its end, which is the function of nature. 440 For how would it be nourished? | 434 b 1 | For the stationary ones this is indeed present where they have grown. However, if a body is not stationary and is generated, it is not possible for it to have a soul and an understanding that is capable of discerning but not to have perception—indeed, even if it is not generated.

Key Concepts

• The nutritive soul, then, must be possessed by everything that is alive and has a soul from its birth until its death.
• For what has been born must have growth, a prime of life, and a time of withering away, and these things are impossible without nourishment.
• The nutritive capacity must therefore be present in | 434 a 25 | all things that grow and wither away.
• Perception, on the other hand, is not necessarily present in all living things, since those things that have a body that is simple cannot have touch, and neither can those that are not receptive of the forms without the matter.
• Animals, though, must have perception, | 434 a 30 | and without this nothing can be an animal, | 434 a 30a | if nature does nothing pointlessly.
• For all things that are | 434 a 31 | by nature are for the sake of something or will be concomitants of those things that are for the sake of something.
• Every body that can perambulate, then, if it did not have perception, would perish and fail to arrive at its end, which is the function of nature.
• For how would it be nourished?

Context

Opening of III.12 (434a25–b1), where Aristotle sums up the universality of the nutritive soul, restricts perception to animals, and uses his teleological axiom to argue that any naturally perambulatory living body must have perception in order to attain its natural end.