NATURAL SCIENCE TO GENERAL SCIENCE. 13 



tific work, it is necessary to discover every fact by 

 careful observation, then to verify and collate them, and 

 to separate what is important from what is not. All 

 this requires a man with a thorough grasp, both of the 

 object of the compilation, and of the matter and methods 

 of the science ; and for such a man every detail has its 

 bearing on the whole, and its special interest. Otherwise 

 dictionary-making would be the vilest drudgery imagin- 

 able. 1 That the influence of the progressive development 

 of scientific ideas extends to these works is obvious from 

 the constant demand for new lexicons, new natural 

 histories, new digests, new catalogues of stars, all denot- 

 ing advancement in the art of methodising and organis- 

 ing science. 



But our knowledge is not to lie dormant in the shape 

 of catalogues. The very fact that we must carry it about 

 in black and white shows that our intellectual mastery of 

 it is incomplete. It is not enough to be acquainted with 

 the facts; scientific knowledge begins only when their 

 laws and their causes are unveiled. Our materials must 

 be worked up by a logical process ; and the first step is to 

 connect like with like, and to elaborate a general concep- 

 tion embracing them all. Such a conception, as the 

 name implies, takes a number of single facts together, 

 and stands as their representative in our mind. We call 

 it a general conception, or the conception of a genus, 

 when it embraces a number of existing objects ; we call it 

 a law when it embraces a series of incidents or occurrences. 

 When, for example, I have made out that all mammals 

 that is, all warm-blooded, viviparous^ animals breathe 

 through lungs, have two chambers in the heart and at 

 least three tympanal bones, I need no longer remember 

 these anatomical peculiarities in the individual cases of 

 the monkey, the dog, the horse, and the whale ; the 



1 Condendaque lexica mandat damnatis. TR. 



