40 Greek Biology 



as organic or inorganic that is a distinction of the seven- 

 teenth-century physiologists nor does he think of things 

 as divided into animal, vegetable, and mineral that is a dis- 

 tinction of the mediaeval alchemists, but he thinks of "things 

 as either with soul or without soul (eij.\l/v\a or atyvxa). 



His belief as to the relationship of this soul to material things 

 is a difficult and complicated subject which would take us far 

 beyond the topics included in biological writings to-day, but 

 he tells us that ' there is a class of existent things which we call 

 substance, including under that term, firstly, matter, which 

 in itself is not this nor that ; secondly, shape or form, in virtue 

 of which the term this or that is at once applied ; thirdly, the 

 whole made up of matter and form. Matter is identical with 

 potentiality, form with actuality,' the soul being, in living 

 things, that which gives the form or actuality. * Of natural 

 bodies ', he continues, ' some possess life and some do not : 

 where by life we mean the power of self-nourishment and of 

 independent growth and decay'. 1 It should here be noted 

 that in the Aristotelian sense the ovum is not at first a living 

 thing, for in its earliest stage and before fertilization it does 

 not possess soul even in its most elementary form. 



' The term life is used in various senses, and, if life is 

 present in but a single one of these senses, we speak of a 

 thing as living. Thus there is intellect, sensation, motion 

 from place to place and rest, the motion concerned with 

 nutrition, and, further, [there are the processes of] decay and 

 growth,' all various meanings or at least exhibitions of some 

 form of life. Hence even ( plants are supposed to have life, for 

 they have within themselves a faculty and principle whereby 

 they grow and decay. . . . They grow and continue to live so 

 long as they are capable of absorbing nutriment. This form 

 of life can be separated from the others . . . and plants 

 have no other faculty of soul at all.' but only this lowest 



1 De anima^n, i, ii. 



