14 ZOOLOGICAL PHILOSOPHY 



Unfortunately this method is not sufficiently used in the study 

 of natural history. The recognised necessity for close observation 

 of special objects has produced a habit of not going beyond these 

 objects with their smallest details. They have thus become for most 

 naturalists the chief subjects of study. This would, however, not 

 really be a drawback for natural science, were it not for the steady 

 refusal to see in the observed objects anything besides their form, 

 dimensions, external parts, colour, etc., but those who give themselves 

 up to such a study are contemptuous of the higher ideals, such as the 

 enquiry into the nature of the objects which occupy them, into the 

 causes of the modifications or variations which these objects undergo, 

 and into the relations of these same objects with each other and with, 

 all other known objects, etc., etc. 



It is because the method which I have just named is insufficiently 

 followed out that we find so much divergence in what is taught on 

 this subject, both in works on natural history and elsewhere. Those 

 who have gone in exclusively for the study of species find it very 

 difficult to grasp the general affinities among objects ; they do not 

 in the least appreciate nature's true plan, and they perceive hardly 

 any of her laws. 



I am convinced that it is wrong to follow a method which so greatly 

 limits ideas. I find myself on the other hand obliged to bring out 

 a new edition of my SysUme des animaux sans vertibres, since the 

 rapid progress of comparative anatomy and the new discoveries of 

 zoologists, together with my own observations, enable me to improve 

 that work. I have accordingly collected into a special work, under 

 the title of Zoological Philosophy, (1) the general principles at stake 

 in the study of the animal kingdom ; (2) the observed facts which, 

 require to be considered in that study ; (3) the principles which, 

 regulate the most suitable classification of animals, and an arrange- 

 ment of them in their natural order ; (4) lastly, the most important of 

 the results which flow naturally from the accumulated observations 

 and facts, and which constitute the true foundation of the philosophy 

 of science. 



The Zoological Philosophy is nothing but a new edition, re-cast, 

 corrected and much enlarged, of my work entitled Recherches sur 

 les corps vivants. It is divided into three main divisions, and each 

 of these divisions is broken up into separate chapters. 



Thus, in the first division, which sets forth the essential observed 

 facts and the general principles of the natural sciences, I shall begin 

 by a discussion of what I call artifi,cial devices used among the sciences 

 in question. I shall deal with the importance of the consideration 

 of affinities, and with the notion that should be conveyed, when 



