COLLIGATIVE RELATIONS AND SCIENTIFIC LAWS 137 



But at this point our chief concern is with the MendeHan laws' con- 

 notations. These are, of course, enormous: from them derive the 

 foundation blocks of classical genetics. And even the predictive fail- 

 ures of the Mendelian laws, in other than a statistical sense, are rich 

 in connotations, e.g., as regards the linkage of genes in chromosomes. 



COLLIGATIVE RELATIONS IN OTHER GUISES 



Everything called a scientific law is not necessarily a colligative re- 

 lation; everything serving as a colligative relation is not necessarily 

 restricted to the function of a more or less efficient predictive device. 

 The relation may have connotations that, as we have just seen, sup- 

 ply suggestive pointers for theory construction. Having achieved 

 theoretical accommodation, the relation acquires a new footing in the 

 heuristic apparatus, as something entailed by a theory there estab- 

 lished. There, too, it may appear in generalized form not as deduc- 

 tion from postulates but as in itself a postulate; e.g., the conservation 

 of energy as first conceived by Joule is a colligative relation before it 

 becomes the first principle of thermodynamics. In the heuristic ap- 

 paratus again the law may appear as a substantive principle, taken 

 for granted and temporarily conventionalized while v/e use it in our 

 study of other laws. Yet again, a law may be involved in establishing 

 the denotations, and in particular the alternate "equivalent " denota- 

 tions, of an indicative concept; e.g., Boyle's law becomes part of the 

 definition whenever we rely on a McLeod gauge to measure a "pres- 

 sure" too small to be measured with an ordinary manometer. Apart 

 from any status as colligative relation, a scientific law may thus as- 

 sume manifold guises and functions, some of which we shall ex- 

 amine later. 



