142 Notes, i. I. 



•'Birds" for instance or the class "Fishes" is a genus, but the larger division or sub- 

 kingdom ♦' Sanguineous animals," i.e. Vertebrata, is not a genus. But in fact A. is very 

 far from adhering strictly to this definition of genus. He uses the term in the most lax 

 manner to express any group however large and however small. Thus we have "the 

 genus of plants," "the genus of animals," where genus equals kingdom. "There 

 are many genera of bees," where it is equivalent to species ; and yet in another place 

 "the genus of bees." So again "one genus of oxen has a bone in the heart," where 

 genus answers to variety. This vague use of the term makes it impossible to translate 

 it invariably by the same English word. I have therefore rendered it variously — 

 genus— order— tribe— class— natural group — kind, etc., as seemed most convenient in 

 each separate case. « 



3. Aristotle recognised four causes, or necessary conditions of existence ; the Material, 

 Formal, Efficient, and Final. Everything that is made is made of matter ; has a definite 

 form ; is brought into being by some agency ; and brought into being for a purpose 

 [^Phys. ii. 3). Take a statue for example. Its material cause is marble ; its formal 

 cause the shape into which that marble is fashioned ; its efficient or motor cause the 

 sculptor's art ; its final cause the realisation of the artist's idea. In the text, however, 

 A. speaks as it there were but two causes. For, as he says elsewhere {Phys. ii. 7, 2), 

 the fbrmal, efficient, and final causes are often one and the same. This is the case 

 with living beings. The body constitutes their material cause ; the soul the remaining 

 three {D.A. ii. 4, 5). The soul is the formal cause ; for just as the addition of the 

 impression to wax forms the seal, or as the addition of sphericity to the metal forms the 

 copper globe, so is it the addition of the soul to the body that forms the living organism. 

 The soul is the efficient cause ; because it is the soul which, imparted in the generative 

 fluid of the father, effects the development of the inert matter furnished by the mother, 

 and is the motor agent in its after activities. Lastly the soul is the final cause of the 

 organism, for the activity of the soul is the purpose aimed at by nature in its construction 

 {D. P. i. s, 12). 



4. A. divides the sciences into three groups {Metaph. v. i). Firstly the Theoretical, 

 •which are purely intellectual and not concerned with action. In this are comprised 

 Metaphysics, Pliysics, and Mathematics. Secondly the Practical ; and thirdly the 

 Constructive or Artistic. The Practical and the Artistic comprehend action as well 

 as intelligence ; but differ from each other, in that the Practical have no other result 

 than the action itself; whereas the Constructive or Artistic, where the action is over, 

 leave as its result a substantial product. 



The contrast in the text (from which I omit the rt) is between the theoretical and 

 the constructive sciences ; and the points of contrast are as follows. The theoretical 

 philosopher starts from certain eternal facts or verities (rb iv) — the mathematician for 

 instance from his axioms — and proceeds to deduce from these those consequences which 

 are linked to them by absolute necessity. The artist, on the other hand, or nature, 

 the chief of artists, starts from an ideal conception, not yet existent in matter, but to 

 be realised in the future (tJ> ialt^iivov). Starting from this, he reasons backwards 

 through the antecedent steps that are necessary, if the conception is to be realised. 

 The realisation of my conception E, he says, requires first the realisation of D ; 

 if Z> is to be produced, there must previously be C; C again requires B for its 

 production ; and so farther and farther back, until he reaches a link in the chain of 

 antecedents, let us say A, the material production of which is within his power. Here 

 the ratiocination ceases, and construction begins. He produces A ; then by means of A 

 produces B, from B produces C, and so on, retracing his previous steps, until he 



