A gene tic Scie7tce 301 



further procedure of so arranging the conditions that the 

 phenomena are caught going through certain of the more 

 recondite phases of their behaviour; this last is called 

 experimentation. 



Such is the method of the * physical ' sciences — physics 

 and chemistry — as distinguished from the 'natural* or 

 biological sciences. The postulates of this procedure 

 are (i) wiiformity — which means no more nor less than 

 * agenetic ' ^ regularity, or the absence of any sort of 

 change which is not exhaustively interpreted in terms of 

 preceding change of the same order. With this there is 

 (2) the postulate of some sort of laivftilness — the require- 

 ment that natural phenomena be not capricious in their 

 behaviour, but that experience so order itself by law that 

 illustrations of what the law means, or what it has come 

 to mean on the basis of just these experiences, may 

 actually and at any time be found. As representing one 

 way of looking at science this * agenetic ' point of view is 

 made extreme in the claim that this procedure, which 

 tacitly fails to recognize the genetic, or which explicitly 

 confines itself to the ' agenetic,' is the exclusive procedure 

 and exhausts the resources of science. 



Such a view, which I shall henceforth call the ' agenetic 

 theory '2 of science, rests upon certain interesting and 

 important mental movements. If we hold that the growth 

 of experience, whereby it reaches maturity in what we 

 call 'thought,' is by the formation of certain categories or 

 habits, then it seems necessary to say that, so far as 

 experience is organized at all, it must be in these catego- 

 ries ; and further, that a category itself reflects something 



1 A term meaninj^, of course, not genetic, as genetic is explained below.^ 



2 Positively it is the point of view of * quantitative ' or exact science. \ 



