CHAPTEE XLV. 



REMARKS ON THE LOGIC OF THE SCIENCES. 



The more 

 special and 

 complex 

 is the 

 subject of 

 a science, 

 the less is 

 mathe- 

 matics 

 applicable 

 to it. 



In con- 

 nexion 

 with this, 

 the facts 

 of life are 

 in some 

 degree in- 

 definite. 



AS we have seen in the preceding chapter, different 

 methods of discovery belong to different sciences; 

 thus, demonstration pre-eminently belongs to mathematics, 

 and experiment to chemistry. Mathematical methods have 

 not yet been successfully applied to chemistry, though 

 perhaps it may some day be found possible to do so; 

 but we may positively assert that they never can be 

 applied to the science of life. Indeed it may be stated 

 as a general truth, that the more special and complex 

 are the facts which constitute the subject-matter of a 

 science, the less susceptible is it of mathematical treat- 

 ment. Thus, general dynamics is altogether a mathema- 

 tical science; the secondary dynamical sciences (sound, 

 radiance, heat, electricity, and magnetism) are so in great 

 part ; chemistry may perhaps become so ; but the sciences 

 that involve life can never by any possibility become 

 mathematical. 



This peculiarity of the sciences of life is connected 

 with the truth that their facts, even when perfectly 

 well ascertained, are not capable of being determined 

 with the same kind of precision as those of the inor- 

 ganic sciences. In chemistry, for instance, the propor- 

 tions in which two substances combine are in many cases 

 known with perfect numerical accuracy, and are in all 

 cases capable of being so known. In biology, on the 

 contrary, no such accurate determinations are possible: 

 this is not because the quantitative relations are too 

 diflicult to determine ; it is because they are variable. 



