26 ARISTOTLE'S METHOD. 



his ground as he proceeded. He was hke an explorer of a 

 new region, who recognizes its mountain ranges, its chief 

 plains, its great rivers, and, here and there, some minor 

 features which arrest his attention, but who must press 

 forward, with no opportunity for tracing a river to its som-ce 

 or ascertaining the relative positions and heights of the 

 various peaks. "While admitting the importance of obtaining 

 a knowledge of the phenomena by observation, he seems to 

 have been determined to formulate as many generalized 

 statements as possible. He appears to admit this when 

 he says that we must try to state what appears to us 

 (to psuvofjuvov) , nor should this be considered to be of the nature 

 of presumption, but should deserve respect, when anyone, 

 having to deal with matters of very great difficulty and 

 urged by a desire for investigating philosophy, contents 

 himself with shght data.* 



A further cause of failure, closely connected with 

 Aristotle's apparent willingness to content himself with slight 

 data, and mere approximations to the truth, deserves special 

 mention. It is clear that any defect arising from insufficient 

 data would have to be remedied in some way, and Aristotle, 

 like many other ancient Greek philosophers, sometimes tried 

 to do this by relying on certain ideas which were treated by 

 him as if they were more authoritative than the data them- 

 selves. These ideas were brought forward, often without 

 any apparent consideration as to whether or no they were 

 relevant to the question at issue, and used in much the same 

 way as axioms and postulates are used by geometricians. 

 The result was a remarkable mixture of inductive and 

 deductive reasoning. 



The arguments which led Aristotle to conclude that there 

 could not be a separate void, + and that the blood of the right 

 chamber of the heart and of the right side of the body is 

 hotter than that of the left,C furnish examples of the defects 

 of method caused by the use of ideas of the kind referred to 

 above. 



Aristotle's arguments against the existence of a separate 

 void are too long to be given in full, but the following is an 

 epitome of what seem to be the chief parts of them. In a 

 void, if this existed, a body could not be in motion, for a 

 void, being a mere privation of matter, could not present 

 differences of position and direction, such as above and below, 



* De Ccelo, ii. c. 12, 2916. + Physics, iv. c. 8. 



X p. A. ii. c. 2, &48fl, iii. c. 4, 667rt. 



V 



I 



