620 Child, Driesch's harmonic equipoteotial systems in form-regulation. 



correct. A mechanistic interpretation is possible if each part con- 

 stitutes apart of only one machine at any given time, and there 

 is no reason to suppose that it constitutes anything more than this. 



To put the matter briefly, the act of separation of the part, 

 or of dislocation of the parts establishes directly or indirectly the 

 conditions for the formation of a new machine, which did not exist 

 as such before this act. Before there existed merely a potence, 

 i. e., a possibility of forming this new machine under certain 

 conditions: this potence exists in the constitution of the original 

 machine and in the conditions, but it does not possess the space 

 configuration of the new machine itself. The formation of new 

 machines which did not exist as such previously is a familiar pheno- 

 menon in inorganic nature, e. g., in the formation of a flame from 

 a combustible substance under certain conditions. 



But whether the new machine shall be similar to the old in 

 cases of regulatory development, and indeed whether any new 

 machine shall be formed, depends both upon the constitution of 

 the part or parts and upon the conditions which are present. It 

 is possible, for example, to prevent the formation of a hydranth 

 in a piece of Tubularia stem in many different ways, e. g., by in- 

 serting the end in sand, by closing it with wax etc. If the harmonic 

 equipotential system which Tubularia is supposed to be can accom- 

 plish the processes of development independently of external con- 

 ditions the reason for the failure to develop under these conditions 

 is not apparent. 



Driesch states the case as if the formation of the new whole 

 occurred in all cases, but this is very far from being true. I am 

 of com\se aware that Driesch assumes the entelechy acts in con- 

 junction with „mechanical" conditions or employs these conditions 

 as „Mittel", but I fail to see the necessity for assuming the exi- 

 stence of the entelechy and the assumption of „Mittel" seems to 

 be merely a second hypothesis for the purpose of rendering the 

 first plausible. 



Driesch's use of the word „beliebig" is a good illustration of 

 the case in point. In the first statement of his „proof" quoted 

 above he says: „eine Maschine bleibt nicht dieselbe, wenn man ihr 

 beliebige Teile nimmt", in the second „diese Ausgänge aber sind 

 beliebig". 



In experiment, however, it is not in the least difficult to isolate 

 pieces of Tubularia or of any other of Driesch's harmonic equi- 

 potential systems which are incapable of forming a whole, i. e., 

 which do not remain the same, or as I should prefer to put it, 

 do not possess the same potences as the whole. Evidently then 

 the organism, lilie Driesch's postulated machine does not remain 

 the same „wenn man ihm beliebige Teile nimmt". In all cases so 



