GENERATION OF ANIMALS, II. i. 



formed by the processes of the arts. Heat and cold 

 soften and harden the iron, but they do not produce 

 the sword ; this is done by the movement of the 

 instruments employed, which contains the logos of the 

 Art ; since the Art is both the principle " and Form 

 of the thing which is produced ; but it is located 

 elsewhere than in that thing, whereas Nature's 

 movement is located in the thing itself which is 

 produced, and it is derived from another natural 

 organism which possesses the Form in actuality. As 

 for the question whether the semen possesses Soul or 

 not, the same argument * holds as for the parts of 

 the body, viz.. (a) no Soul will be present elsewhere 

 than in that of which it is the Soul ; (6) no part of 

 the body \\i\\ be such in more than name ^ unless it 

 has some Soul in it (e.g., the eye of a dead person). 

 Hence it is clear both that semen possesses Soul, and 

 that it is Soul, potentially. And there are varying 

 degrees in which it may be potentially that which it 

 is capable of being — it may be nearer to it or further 

 removed from it (just as a sleeping geometer is at a 

 further remove than one who is awake, and a waking 

 one than one who is busy at his studies). So ** then, 

 the cause of this process of formation is not any part 

 of the body, but the external agent which first set 

 the movement going — for of course nothing gener- 

 ates itself,* though as soon as it has been formed a 

 thing makes itself grow.^ That is why one part is 

 formed first, not all the parts simultaneously. And 

 the part which must of necessity be formed first is 

 the one which possesses the principle of growth : be 

 they plants or animals, this, the nutritive, faculty is 

 present in all of them alike (this also is the faculty 



f Cf. below, 735 a 22, 740 a 19 ff. 



155 



