THE AIM AND ACHIEVEMENTS OF SCIENTIFIC METHOD. 83 



a new kind of equivalence to one another, which we may 

 express by saying that they are "chemically equal/'* just 

 as by saying that two bodies have "equal mass" we imply 

 that they display a definite kind of dynamical equivalence 

 to one another.f The atom a concept which entered into 

 modern science in the seventeenth century from a phrtesophic 

 context in which its function was to harmonize the contradic- 

 tions of Being and Becoming thus comes to be " the qualita- 

 tive and quantitative expression of the powers possessed by 

 substances to change into others/'J an expression which 

 contains no more than an historical allusion to the view 

 that " matter " is composed of actual minute indivisible 

 particles. In possession of the concept of a definite Objective 

 relation constantly showing itself between definite Objective 

 facts the facts of chemical combination we have, indeed, 

 reached the point at which at least one particular grou"p of 

 elements of the " picture " and the " object " coincide/; |j and we 

 have no further use, except, possibly, for purposes of exposition 

 and the like, of the earlier concept which first enabled us 

 to bring intelligibility into this region of Objective fact&IL 



t 



32. 



Whenever in the foregoing allusion has been made to the 

 fully determined particulars of ax province of the Objective, it 

 is highly probable that the reader- will have assumed that 

 quantitative or at least numerical determinations were intended. 

 It is a commonplace that Science only moves with security 



m 



where she can measure. Quite recently we have seen this 



* Divers, op. cit., pp. 559 and 563. 

 t Vide infra, p. 99 ; Divers, op. cit., p. 562. 

 I Divers, op. tit., p. 566. 

 P. 559. 

 || Supra, p. 72. 



IT Cf. an article " On Methods of Teaching the Atomic Theory," con- 

 tributed by the writer to The School World, February, 1906. 



G 2 



