Child, Driesch's harmonic equipotential systems in form regulation. 579 



„harmonisch-äquipoteiitielle Systeme mit primärer Richtungsorgani- 

 sation sich bei Ausschluss äußerer Ursachen differenzieren. Unter 

 dem Ausdruck „äußere Ursachen" sind hier nicht nur im strengen 

 Sinne die Faktoren der Außenwelt verstanden, sondern wenn die 

 Differenzierung eines Systems in Frage kommt, das Teil eines Orga- 

 nismus ist, auch alle etwa von anderen Teilen desselben auf ihn 

 geschehenden Beeinflussungen, wie sie z. B. in attraktiven, taktischen 

 Reizwirkungen, bei Berührungen etc. vorliegen; auch solche Reizarten 

 müssen also, damit unser Problem auftrete, ausgeschlossen sein. 



„Sind auch sie, und damit die äußeren Ursachen überhaupt, 

 ausgeschlossen, so wird eben deshalb die Lokalisation der Differen- 

 zierungsvorgänge ein Problem, weil sich mit Hilfe der von uns 

 wissenschaftlich gekannten Ursachsarten nicht verstehen lässt, wie 

 es nun an jenem in sich prospektiv gleichartigen Material zum 

 Eintritt einer Verschiedenheit gerade an diesem oder gerade an 

 jenem Ort komme." 



Here Driesch apparently becomes involved in serious error. 

 If I understand him, his argument is essentially that there is nothing 

 among the causes known to science to account for the localization 

 of morphogenetic processes in material which is prospectively alike 

 and which differentiates with exclusion of all factors external to it. 

 This argument seems to involve the tacit assumption that where 

 prospective likeness exists present likeness must also exist, for if 

 differences exist within the material then a basis for further locali- 

 zation exists, at least a possible basis, and Driesch's problem 

 cannot become a real problem until it is demonstrated that such 

 existing differences are not the basis of further localization. Actually, 

 however, present likeness does not follow from prospective likeness. 

 Material at present widely different may still possess the capacity 

 for producing like effects under conditions different from those now 

 existing. In an organism the parts may possess similar prospective 

 potences but may at present differ from each other w^idely, since 

 they are or have been under different conditions. Moreover, the 

 past or present relations may play a part in determining which of 

 the prospective potences shall be realized in a particular case. 



A simple illustration will serve to make this point clear: All 

 units (theoretically all atoms) of a given substance, e. g., oxygen, 

 are prospectively alike, i. e., they possess the same potentialities, 

 yet oxygen in combination with carbon (CO or CO2) is different 

 from oxygen in combination with hydrogen (HjO). Moreover the 

 oxygen in these different substances may behave differently when 

 the substances are placed under identical conditions, i. e., different 

 potentialities may be realized in the two cases. Yet under these 

 and other conditions the prospective potences of the oxygen remain 

 the same. 



37* 



