ADDRESS. 7 



Tlie Coii></riicfioii of a Model of Kaluvc. 



A natural philosopher, to use the old phrase, even if only possessed of 

 the most superficial knowledge, would attempt to bring some order into 

 the results of his observation of Nature by grouping together statements 

 with regard to phenomena which are obviously related. The aim of 

 modern science goes far beyond this. It not only shows that many 

 phenomena are related which at first sight have little or nothing in 

 common, but, in so doing, also attempts to explain the relationship. 



Without spending time on a discussion of the meaning of the word 

 ' explanation,' it is sufficient to .say that our efforts to establish relation- 

 ships between phenomena often take the form of attempting to prove 

 that, if a limited number of assumptions are granted as to the constitu- 

 tion of matter, or as to tlie existence of quasi-material entities, such as 

 caloric, electricity, and the ether, a wide range of observed facts falls into 

 order as a necessary consequence of the assumptions. The question at 

 issue is whether the hypotheses which are at the base of the scientific 

 theories now most generally accepted are to be regarded as accurate 

 descriptions of the constitution of the univei'se around us, or merely as 

 convenient fictions. 



Convenient fictions be it observed, for even if they are fictions they 

 are not useless. From the practical point of view it is a matter of 

 secondary importance whether our theories and assumptions are correct, 

 if only they guide us to results which are in accord with facts. The 

 whole fabric of scientific theory may be regarded merely as a gigantic 

 ' aid to memory ' ; as a means for producing apparent order out of dis- 

 order by codifying the observed facts and laws in accordance with an 

 artificial system, and thus arranging our knowledge under a comparatively 

 small number of heads. The simplification introduced by a scheme which, 

 however imperfect it may be, enables us to argue from a few first principles, 

 makes theories of practical use. By means of them we can foresee the 

 results of combinations of causes which would otherwise elude us. We 

 can predict future events, and can even attempt to argue back from the 

 present to the unknown past. 



But it is possible that these advantages might be attained by means 

 of axioms, assumptions, and theories based on very false ideas. A 

 person who thought that a river was really a streak of blue paint 

 might learn as much about its direction from a map as one who knew 

 it as it is. It is thus conceivable that we might be able, not indeed 

 to construct, but to imagine, something more than a mere map or 

 diagram, something which might even be called a working model of 

 inanimate objects, which was nevertheless very unlike the realities of 

 nature. Of coui'se, the agreement between the action of the model and 

 the behaviour of the things it was designed to represent would probably 

 be imperfect, unless the one were a facsimile of the other ; but it is con- 

 ceivable that the correlation of natural phenomena could be imitated. 



