10 INTRODUCTORY [ch, 



of the bodily energies, and the long battle against the cold and 

 darkness which is death. With these weighty problems I am not 

 for the moment concerned. My sole purpose is to correlate with 

 mathematical statement and physical law certain of the simpler 

 outward phenomena of organic growth and structure or form: 

 while all the while regarding, ex hypothesi, for the purposes of 

 this correlation, the fabric of the organism as a material and 

 mechanical configuration. 



Physical science and philosophy stand side by side, and one 

 upholds the other. Without something of the strength of physics, 

 philosophy would be weak ; and without something of philosophy's 

 wealth, physical science would be poor. " Rien ne retirera du 

 tissu de la science les fils d'or que la main du philosophe y a 

 introduits*." But there are fields where each, for a while at 

 least, must work alone ; and where physical science reaches its 

 limitations, physical science itself must help us to discover. 

 Meanwhile the appropriate and legitimate postulate of the 

 physicist, in approaching the physical problems of the body, is 

 that with these physical phenomena no ahen influence interferes. 

 But the postulate, though it is certainly legitimate, and though 

 it is the proper and necessary prelude to scientific enquiry, may 

 some day be proven to be untrue ; and its disproof will not be to 

 the physicist's confusion, but will come as his reward. In dealing 

 with forms which are so concomitant with life that they are 

 seemingly controlled by hfe, it is in no spirit of arrogant assertive- 

 ness that the physicist begins his argument, after the fashion of 

 a most illustrious exemplar, with the old formulary of scholastic 

 challenge, — An Vita sit ? Dico quod non. 



The terms Form and Growth, which make up the title of this 

 little book, are to be understood, as I need hardly say, in their 

 relation to the science of organisms. We want to see how, in 

 some cases at least, the forms of living things, and of the parts 

 of living things, can be explained by physical considerations, and 

 to reahse that, in general, no organic forms exist save such as 

 are in conformity with ordinary physical laws. And while growth 

 is a somewhat vague word for a complex matter, which may 



* Papillon, Histoire de la philosophie moderne, i, p. 300. 



