92 MEMOIR OF ARISTOTLE. 



ing tv> the phenomena of the material universe, he 

 employed himself in deducing consequences from 

 metaphysical and mathematical data ; arguing from 

 the mere abstract notions of the mind, to the reali- 

 ties of the external world. The first portion of his 

 physical philosophy, contained in the treatise en- 

 titled Natural Auscultations, is devoted to inquiries 

 into the principles of the science, in order to ascer- 

 tain those fundamental conceptions of its several ob- 

 jects, from which all conclusions concerning them 

 are deduced. These principles he reduces to three : 

 I . Matter ; 2. Form ; 3. Privation ; so well known 

 and so much perverted in the jargon of the schools. 

 The design of his inquiry being to obtain, by physical 

 analysis, an ultimate point to which all the various 

 notions involved in the speculation of nature might 

 be inferred, he proceeds to explain these natural ob- 

 jects to be such as have in themselves a principle of 

 motion and rest, as contrasted with works of art, the 

 principle of which is in the artist. From examining 

 this inherent principle, and shewing how it operates 

 in producing the ordinary appearances observed in 

 the world around us, he is led to account for the 

 processes of generation and corruption, and the 

 changes which occur in bodies by alteration, mix- 

 ture, locomotion, increase and decrease, &c. 



The great doctrine of the ancient physics, " that 

 nothing could be produced out of nothing," according 

 to his theory, required no distinct consideration. In- 

 quiring into nature simply as a principle of motion, 



