INDUCTION. IC>9 



are: (i) the principle of serviceable asso- 

 ciated habits; (2) the principle of antithesis; 

 (3) the principle of actions due to the constitu- 

 tion of the nervous system, independently from 

 the first of the will, and independently to a 

 certain extent of habit. It is to be remarked 

 of these three principles that they are induc- 

 tions, and that they are vague on two accounts: 

 they are in part so general that it might prove 

 difficult to bring them to a crucial test with 

 the hope of proving or disproving them; and 

 the only test to which they have been put is 

 that of explaining the very facts from which 

 they were drawn. They have not been used to 

 make further discoveries; they represent well 

 the type of inductions based on many carefully 

 studied facts, but unsupported by a subsequent 

 deductive research. 



A simpler case of induction is his inference 

 concerning the age at which characters appear 

 which are inherited by one or both sexes. " It 

 is in itself probable," he said, "that any char- 

 acter appearing at an early age would tend to 

 be inherited equally by both sexes, for the 

 sexes do not differ much in constitution, before 

 the power of reproduction is gained"; and 

 went on to point out that characters appearing 

 late in one sex would tend to be restricted to 



