INTRODUCTION. 159 



such as the virtues and the vices, for which men are either 

 praised and rewarded or reproved and punished. All our know- 

 ledge, therefore, of every kind has to he acquired. But this is 

 not the place to inquire into the first principles of knowledge. 



I believe, however, that it will not he useless if I premise a 

 few words as to whence and how our knowledge reaches us, 

 both with a view to rendering what I shall say on the subject 

 of generation more readily intelligible, and of removing any 

 doubts that may arise out of this opinion of the Stagirite, 1 who 

 asserts that all doctrine and discipline based on reason are de- 

 rived from antecedent knowledge ; whence it seems to follow 

 that there is either no first knowledge, or that this must be 

 innate, a conclusion which is in contradiction with what has 

 already been stated. 



The doubt, however, is by and by resolved by Aristotle 2 him- 

 self, when he treats of the mode in which knowledge is ac- 

 quired : for after he has taught that all certain knowledge is 

 obtained through syllogism and demonstration, and made it 

 manifest that every demonstrative syllogism proceeds from true 

 and necessary first principles ; he goes on to inquire how prin- 

 ciples become known, and what the faculty is that knows ; at 

 the same time, too, he discusses the question, Whether habits, 

 if not innate, are engendered ; and whether, being innate, they 

 lie concealed ? " We have not," he says, " these habits ; for it 

 happens that they are concealed from those who acquire the 

 most admirable kinds of knowledge through demonstration. 

 If, however, we receive them, not having had them previously, 

 how should we become informed, how learn from non-antece- 

 dent knowledge ? It is obvious, therefore, that they are neither 

 possessed, nor can they be engendered in the ignorant and 

 those who are endowed with no habit. Whence it is essential 

 that some faculty be possessed, not however any which were 



1 Analyt. post. lib. i, c. 1. * Ib. lib. ii, cap. ult. 



