no PROGRESS OF SCIENCE. 



work accomplished rather than by what is imposing in extent 

 and weight. And this has been the guiding principle in the 

 main here. It will explain why the author has credited the 

 great men he mentions with little more than a fraction of 

 their labours a deficiency inherent to the nature of the 

 present work of which he is conscious, and upon which he 

 lays particular stress ; but he trusts he has fairly succeeded in 

 giving at least the main achievements of the scientists he has 

 brought within his survey. In some instances, he has pre- 

 ferred to enunciate a scientific fact in that plain speech which 

 the ordinary reader is likely to apprehend best, rather than in 

 that technical diction which a thorough adept in this or that 

 branch would have adopted. In so wide a scope, in any case, 

 the author confidently relies upon meeting with the indulgence 

 of the experts. These will consider the exiguity of the limits 

 imposed by the plan and object of his book, and they will no 

 doubt own that within those limits he has carried his scheme 

 out in as accurate and conscientious a manner as the matter 

 permitted. 



The progress of modern science, it need hardly be said, 

 necessarily proceeds from the labours carried on and the 

 results obtained before : it is the natural continuation 

 without a break of the work of the XVth and XVIth 

 centuries. 



At this point, the threshold, so to speak, of modern science, 

 it is needful to give the student a short classification of the 

 sciences a matter attended with some difficulty, because 

 every science can be exhibited under two very distinct 

 methods, the historical and the dogmatic ; any other method 

 being nothing but a combination of the two, and whatever the 

 procedure, the classification must always be somewhat artificial, 

 it being impossible to present, with entire exactness, the 

 sciences in their natural connection and according to their 

 mutual dependence. By the historical method knowledge is 

 presented in the order in which it was obtained ; by the dog- 

 matic, knowledge is presented as it may be conceived by an 

 expert who would begin to reconstitute science as a whole. 



Of the many classifications proposed, we shall give 

 COMTE's historical CLASSIFICATION, which is the best of the 



