INTRODUCTION 



The " Causes " 



The four (1) Aristotle begins and ends the G.A. with a paragraph 

 Causes. about Causes " ; and indeed Causes are at the founda- 



tion of all his thought, especially of his theories about 

 animal reproduction and development. 



To know, says Aristotle, is to know by means of 

 Causes (see Anal. Post. 94 a 20). A thing is explained 

 when you know its Causes. And a Cause is that which 

 is responsible, in any of four modes, for a thing's exist- 

 ence. The four Causes are : 



(1) The Final Cause, the End or Object towards which 

 a formative process advances, and for the sake of 

 which it advances — the logos,^ the rational purpose. 

 • (2) The Motive (or Efficient) Cause, the agent which is 

 responsible for having set the process going ; it is 

 that by which the thing is made. 



(3) The Formal Cause, or Form, which is responsible 

 for the character of the course which the process 

 follows (this also is described as the I off os,^ as, express- 

 ing ichat the thing is, or is to be). 



(4) The Material Cause, or Matter, out of ichich the 

 thing is made. 



(2) As an illustration of the theory of Causes the following 

 will serve. Suppose the thing to be explained is a dog. 

 The chronological order of the Causes is different from 

 their logical order. 



(1) The Motive Cause : the male parent which supplied 

 the " movement " that set the process of develop- 

 ment going. 



(2) The Material Cause : the menstrual fluid and the 

 nourishment supplied by the female parent and 

 other nourishment taken after birth. 



(3) The Formal Cause. The embryo and the puppy 

 as it grew into a dog followed a process of de- 

 velopment which had ttje special character proper 

 to dogs. 



" In the translation I have retained tlie traditional rendering " cause " 

 for alrCa, although perhaps in some contexts " reason " or " explana- 

 tion " might have been a closer rendering ; but a variation in the 

 English term might well produce more obscurity than clarity. 



6 See § 10 below. 



xxxviii 



