PARTS OF ANIMALS, II. iii. 



These terms are used in several senses. E.g. 

 " solid " and " fluid " may mean either potentially 

 solid and fluid or actually solid and fluid. Ice 

 and other congealed fluids are said to be solid 

 actually and by accident, though in themselves and 

 potentially they are fluid. On the other hand, earth 

 and ash and the like, when they have been mixed 

 with a fluid, are fluid actually and by accident, but 

 potentially and in themselves they are solid. When 

 these mixtures have been resolved again into their 

 components, we have on the one hand the watery 

 constituents, M'hich are anaplestic,^ and fluid actually 

 as well as potentially, and on the other hand the 

 earthy components which are all solid : and these 

 are the cases where the term " solid " is applicable 

 most properly and absolutely. In the same way, 

 only those things which are actually as well as poten- 

 tially fluid, or hot, or cold, are such in the proper 

 and absolute sense of the terms. Bearing this dis- 

 tinction in mind, we see it is plain that in one way 

 blood is hot [e.g. what is the essential definition of 

 blood ?], for the term " blood " is used just as the 

 term for " boiling water " would be, if we had a 

 special name to denote that ; but in another way, 

 i.e. in respect of its permanent substratum, blood is 

 not hot. This means that in one respect blood is 

 essentially hot, and in another respect is not. Heat 

 will be included in the logos of blood, just as fair- 

 ness is included in the logos of a fair man, and in 

 this way blood is essentially hot ; but in so far as 

 it is hot owing to external influence, blood is not 

 essentially hot. 



A similar argument would hold with regard to the 

 solid and the fluid. And that is why some of these 



e2 131 



