i6 THE GRAMMAR OF SCIENCE 



universe. Yet the distinction between science and meta- 

 physics is often insisted upon, and not unadvisedly, by 

 the devotees of both. If we take any group of physical 

 or biological facts — say, for example, electrical phenomena 

 or the development of the ovum — we shall find that, 

 though physicists or biologists may differ to some extent 

 in their measurements or in their hypotheses, yet in the 

 fundamental principles and sequences the professors of 

 each individual science are in practical agreement among 

 themselves. A similar if not yet so complete agreement 

 is rapidly springing up in both mental and social science, 

 where the facts are more difficult to classify and the bias 

 of individual opinion is much stronger. Our more 

 thorough classification, however, of the facts of human 

 development, our more accurate knowledge of the early 

 history of human societies, of primitive customs, laws, 

 and religions, our application of the principle of natural 

 selection to man and his communities, are converting 

 anthropology, folklore, sociology, and psychology into 

 true sciences. We begin to see indisputable sequences 

 - in groups of both mental and social facts. The causes 

 which favour the growth or decay of human societies 

 become more obvious and more the subject of scientific 

 investigation. Mental and social facts are thus not 

 beyond the range of scientific treatment, but their 

 classification has not been so complete, nor for obvious 

 reasons so unprejudiced, as those of physical or biological 

 phenomena. 



The case is quite different with metaphysics and those 

 other supposed branches of human knowledge which claim 

 exemption from scientific control.^ Either they are based 

 on an accurate classification of facts, or they are not. But 

 if their classification of facts were accurate, the application 



1 It is perhaps impossible to satisfactorily define the metaphysician, but 

 the meaning attached by the present writer to the term will become clearer in 

 the sequel. It is here used to denote a class of writers, of whom well-known 

 examples are : Kant, in his later uncritical period (when he discovered that 

 the universe was created in order that man might have a sphere for moral 

 action !) ; the post-Kantians (notably Hegel and Schopenhauer), and their 

 numerous English disciples, who " explain " the universe without having even 

 an elementary knowledge of physical science. 



