CHAPTEK XXVni. 



NECESSARY TRUTHS AND THE EFFECTS OF EXPERIENCE. 



In this final chapter I shall treat of what has sometimes 

 been called psychogenesis, and try to ascertain just how far 

 the connections of things in the outward environment can 

 account for our tendency to think of, and to react upon, 

 certain things in certain ways and in no others, even though 

 personally we have had of the things in question no ex- 

 perience, or almost no experience, at alL It is a familiar 

 truth that some propositions are necessary. We must attach 

 the predicate * equal ' to the subject ' opposite sides of a 

 parallelogram ' if we think those terms together at all, 

 wdiereas we need not in any such way attach the predicate 

 * rainy,' for example, to the subject ' to-morrow.' The dubious 

 sort of coupling of terms is universally admitted to be due 

 to ' experience '; the certain sort is ascribed to the ' organic 

 structure ' of the mind. This structure is in turn supposed 

 hj the so-called apriorists to be of transcendental origin, or 

 at any rate not to be explicable by experience ; whilst by 

 evolutionary empiricists it is supposed to be also due to ex- 

 perience, only not to the experience of the individual, but 

 to that of his ancestors as far back as one may please to 

 go. Our emotional and instinctive tendencies, our irresist- 

 ible impulses to couple certain movements wdth the percep- 

 tion or thought of certain things, are also features of our 

 connate mental structure, and like the necessary judgments, 

 are interpreted by the apriorists and the empiricists in the 

 same warring ways. 



I shall tr}' iu the course of the chapter to make plain 

 three things : 



1) That, taking the word experience as it is universally 

 understood, the experience of the race can no more account 



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