V GENERAL REFLECTIONS AND CONCLUSIONS 293 



a natural organic living- body, life being autonomous nutrition 

 and growth and decay. The activity (e^reAe'xeia) may, however, 

 be latent or patent, passive or active, sleeping or waking, without 

 losing its peculiar characters. This activity is substance (ov<na), 

 but substance as ' form ', as opposed to the material substance 

 of the body ; the living body is therefore also a substance, in 

 a double sense. 



Soul is not, however, identical with the body, but as form, 

 proportion (Aoyos), activity (Wpyeua), essence (TO ri rjv elvai), it 

 is related to the body, mere matter (vArj) and potentiality (Svmjut?), 

 in just the same way as the seal is related to the wax, and the 

 body is the instrument whereby it effects its purposes ; though 

 subsequent in time it is prior in thought to the body, as all 

 activities are to the materials with which they operate. 



At the same time neither it nor its parts are separable from 

 the body, with the exception, possibly, of mind (vovs) ; it is indeed 

 the actual or possible functioning of the body, like the seeing 

 of the eye or the cutting of the axe, and with the disappearance' 

 of the capacity of this functioning the soul itself also perishes. 1 

 Lastly, it is a cause (apx^J *ai airta) in a triple sense : first, as 

 the source of motion, secondly, as that for the sake of which 

 the body exists, and thirdly, as its essence (owia), or formal 

 cause. 2 



The soul is of several kinds, which form together an ascending 

 series, each member of which is necessarily involved in those 

 above it. 3 



The lowest is the nutritive soul (0pe7iriK?/), found in all 

 living things, and the only soul possessed by plants. It is 

 defined as motion in respect of nutrition, decay and growth, 

 processes which involve alteration (dAAouocm) in the body, and 

 its functions (epya) are to utilize the food for the maintenance 

 and reproduction of the form of the body, and to control and 

 limit growth. 



The second is the perceptive soul (ato-07jrtK?j), the possession of 

 which distinguishes animals from plants. Perception is a kind of 

 alteration (dAAoiWts rts), 4 and consists in being moved and affected. 

 The fundamental and indispensable perception is touch (0^77), 



1 De An. II. 1. 2 Ibid. II. 4. 3 Ibid. II. 3, 4. * Ibid. II. 5. 



