ADVANCEMENT OF LEARNING 149 



of what should be affirmed or asserted, but also what we should 

 examine or question; a prudent questioning being a kind of 

 half-knowledge ; for, as Plato justly observes, a searcher must 

 have some general notion of the thing he searches after, other- 

 wise he could never know it when he had found it \f and there- 

 fore, the more comprehensive and sure our anticipation is, the 

 more direct and short will be the investigation. And hence 

 the same topics which conduce to the close examining into our 

 own understandings, and collecting the notices there treasured 

 up, are likewise assistant in drawing forth our knowledge. 

 Thus, if a person, skilful in the point under question, were at 

 hand, as we might prudently and advantageously consult him 

 upon it ; in like manner, we may usefully select and turn over 

 authors and books, to instruct and inform ourselves about those 

 things we are in quest of. 



But the particular topical invention is much more conducive 

 to the same purposes, and to be esteemed a highly fertile thing. 

 Some writers have lately mentioned it, but it is by no means 

 treated according to its extent and merit. Not to mention the 

 error and haughtiness which have too long reigned in the 

 schools, and their pursuing with infinite subtilty such things as 

 are obvious, without once touching upon those that lie remote, 

 we receive this topical invention as an extremely useful thing, 

 that affords certain heads of inquiry and investigation appro- 

 priated to particular subjects and sciences. These places are 

 certain mixtures of logic and the peculiar matter of each sci- 

 ence. It is an idle thing, and shows a narrow mind, to think 

 that the art of discovering the sciences may be invented and 

 proposed in perfection from the beginning, so as to be after- 

 wards only exercised and brought into use ; for men should be 

 made sensible that the solid and real arts of invention grow up 

 and increase along with inventions themselves ; so that when 

 anyone first comes to the thorough examination of a science, 

 he should have some useful rules of discovery ; but after he 

 hath made a considerable progress in the science itself, he may, 

 and ought, to find out new rules of invention, the better to lead 

 him still further. The way here is like walking on a flat, where, 

 after we have gone some length, we not only approach nearer 

 the end of our journey, but also have a clearer view of what 

 remains to be gone of it ; so in the sciences, every step of the 

 way, as it leaves some things behind, also gives us a nearer. 



