THE SCIENCES 27 



constitutes what scientists mean by knowledge, and 

 is the only knowledge which men can possess. 



Knowledge may be concerned either with single 

 particulars of experience, whether physical or super- 

 physical, or with numerous particulars, viewed to- 

 gether and in their mutual relations. Now it is the 

 function of sciences to develop the latter kind of knowl- 

 edge, and scientific knowledge is generalized knowledge. 

 In more specific terms, the function of a science is to 

 investigate, generalize, co-ordinate, and reduce to intel- 

 ligible unity all that can be ascertained concerning some 

 department or aspect of reality. The subject-matter of 

 every science is some department or aspect of the 

 knowable, which in its totality is assumed to constitute 

 a unity and to be susceptible of being to some extent 

 understood in its unity. How far the knowable extends 

 can be determined only by the results of practical efforts 

 to gain knowledge — not by any preconceptions or 

 speculative theories whatsoever. Our theories con- 

 cerning knowledge depend for their validity upon what 

 we already know, and when they are based upon igno- 

 rance they become mere intellectual gymnastics. 



Wherever men have in fact made progress in knowl- 

 edge of reality there is a place for science; and the 

 claim of theology to be a science cannot be rejected 

 except upon the supposition that its ostensible subject- 

 matter is either wholly unknowable or, if knowable, 

 entirely chaotic.^ Science must assume that the uni- 



1 The author has treated of the scientific claim of theology in 

 Introd. to Dog. Theol., ch. i. 



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