152 INTRODUCTION. 



refutation necessary where the truth can be seen with one's 

 proper eyes; where the inquirer by simple inspection finds 

 everything in conformity with reason ; and where at the same 

 time he is made to understand how unsafe, how base a thing 

 it is to receive instruction from others' comments without exa- 

 mination of the objects themselves, the rather as the book of 

 Nature lies so open and is so easy of consultation. 



What I shall deliver in these my Exercises on Animal Gene- 

 ration I am anxious to make publicly known, not merely that 

 posterity may there perceive the sure and obvious truth, but 

 farther, and especially, that by exhibiting the method of inves- 

 tigation which I have followed, I may propose to the studious 

 a new and, unless I mistake, a safer way to the attainment of 

 knowledge. 



For although it is a new and difficult road in studying na- 

 ture, rather to question things themselves than, by turning over 

 books, to discover the opinions of philosophers regarding them, 

 still it must be acknowledged that it is the more open path to 

 the secrets of natural philosophy, and that which is less likely 

 to lead into error. 



Nor is there any just cause wherefore the labour should 

 deter any one, if he will but think that he himself only lives 

 through the ceaseless working of his heart. Neither, indeed, 

 would the way I propose be felt as so barren and lonely, but 

 for the custom, or vice rather, of the age we live in, when men, 

 inclined to idleness, prefer going wrong with the many, to 

 becoming wise with the few through dint of toil and outlay of 

 money* The ancient philosophers, whose industry even we ad- 

 mire, went a different way to work, and by their unwearied 

 labour and variety of experiments, searching into the nature of 

 things, have left us no doubtful light to guide us in our studies. 

 In this way it is that almost everything we yet possess of note 

 or credit in philosophy, has been transmitted to us through 

 the industry of ancient Greece. But when we acquiesce in tho 



