148 The Unity of the Organism 



scores of such agencies, what about the specificity of the 

 formative substances which Loeb himself expressly says was 

 part of Sachs' conceptions? 



Again, how reconcile the contention that thyroid sub- 

 stance or something like it is organ-forming for the legs 

 of a tadpole with the statement quoted a few paragraphs 

 back about mesenchyme cells which give rise to legs? 



The Metaphysical and Logical Weakness of the View 



Obviously Loeb's treatment of this subject contains irre- 

 conciliable contradictions. Is it then worthless? My answer 

 is, no, not by any means. But how comes it that a scien- 

 tist of his great experience and merited distinction can run 

 into such self-destroying speculations and statements, seem- 

 ingly without rational discomfort to either himself or others 

 of the school which he represents? 



The answer takes us back to some of the most funda- 

 mental issues between the elementahst and organismal stand- 

 points, and though not requiring us to palliate in any degree 

 such offenses 'against scientific reasoning, it partly explains 

 how tolerance for such offenses is begotten, and discovers 

 a nucleus of genuine merit in Loeb's position. Bringing the 

 matter to as basal a statement as possible, what we find is 

 that this whole book on the Organism as a Whole is written 

 on' the theory that the only alternative to the assumption 

 of supernaturalism is materialism. Instead of supernatural 

 forces of some sort (Platonic Ideas, entelechies, psychoids, 

 "supergenes") for explaining the organism when regarded 

 as alive and whole, his assumption is that material elements 

 as known to us in inorganic nature are the sufficient causal 

 explanation of organic phenomena. 



Were this theory correct- -were it true that the "vital 

 principle" must either be conceived as supernatural or that 

 the inorganic elements taken by themselves are competent 



