674 



SCIENCE 



[N. S. Vol. XXXVI. No. 933 



was such in some sense and to some degree, I 

 should have supposed that Professor Jen- 

 nings would have given consideration, in 

 reading this phrase, to the qualifying ad- 

 jective "wholesale." By a "wholesale inde- 

 terminism " I intended to designate precisely 

 that extreme doctrine which Jennings in his 

 paper had apparently ascribed to the author of 

 " The Science and Philosophy of the Organ- 

 ism." That doctrine Jennings had formu- 

 lated as follows (italics mine) : 



All living things are complexes of great num- 

 bers of chemicals so that the conditions under 

 which entelechy comes into play are always real- 

 ised. We may therefore expect its action at every 

 step in our work; we must be prepared at all 

 times to find the same physical configuration 

 giving rise now to one result and now to another. 

 (Science, June 16, 1911, p. 932.) 



Such a view would mean that, in organisms, 

 not merely behavior but also all morphogen- 

 etic and psychological processes would be ab- 

 solutely variable and unpredictable, that no 

 amount of past experience of vital phenomena 

 would justify even the slightest anticipation 

 of any uniformity in their future sequences. 

 This doctrine, if accepted, would, as Jennings 

 rightly points out, make biology as a science 

 impossible and compel us to regard biological 

 investigators as engaged in a " hopeless task " 

 {ibid.). If Drieseh adheres to this "whole- 

 sale experimental indeterminism," and takes 

 this extreme view c5 the impossibility of gen- 

 eralization and prediction in biology, I must 

 frankly confess that I had not gathered the 

 fact from his Gifford lectures. And I must 

 add that I even yet remain unconvinced that 

 he does so. If he does, he ought in con- 

 sistency to lead a movement for the suppres- 

 sion of physiological laboratories. I am 

 strengthened in my disbelief that Drieseh 

 cherishes any such fell designs against the 

 happiness of experimental investigators in 

 biology by the fact that another letter of his 

 to Professor Jennings — which the latter does 

 not quote, but which he has kindly permitted 

 me to see — contains the following words: 



Practically, we may say that complete knowl- 

 edge of the physico-chemical constitution of a 



given egg in a given state and of the behavior 

 following this constitution in one case, implies the 

 same knowledge for other cases (in the same spe- 

 cies) with very great probability. But this is a 

 probability in principle and can never be more. 

 It would not even be a probability, in the ease 

 that we did not know the origin (or history) of 

 a given egg in a given state, viz., that the egg 

 is the egg of, say, an ascidian. But to know this 

 history or origin is, of course, already more than 

 simply to know "the physico-chemical constitu- 

 tion" and its consequences in one case (what 

 suffices in the realm of the unorganie). It may 

 be that the eggs of fishes, echinides and birds are 

 the same in all essentials of the physico-chemical 

 constitution.' There happens something very dif- 

 ferent in the different cases on account of the 

 different ' ' enteleehies. ' ' In spite of this, we know 

 what will happen with great probability from one 

 case if we know that this egg "comes from a 

 bird" and that the other "comes from an 

 echinid. "... Therefore, practically, ' ' experi- 

 mental indeterminism" is not a great danger for 

 science. [Italics in the original.] 



This appears to me to be a tolerably perti- 

 nent passage, which might well have been in- 

 eluded among Jennings's selections from his 

 correspondence with Drieseh. It seems equiv- 

 alent to a statement that the sort of indeter- 

 minism which Drieseh professes is virtually 

 negligible, so far as the every-day, practical 

 purposes of the experimentalist are concerned. 

 If Jennings had considered this passage in 

 connection with the others which he quotes, he 

 would not, I am sure, have contended that 

 " Dr. Driesch's statements of the matter are 

 fully as strong" as his own: they obviously faU 

 very far short of his own. The experimental 

 indeterminism in them is not at all of the 

 " wholesale " sort." Possibly Jennings holds 



' The reader will observe that this particular 

 proposition Drieseh gives as merely possibly true. 

 It has, in fact, no sort of logical connection with 

 his arguments from morphogenesis and restitution. 

 Not only do those arguments not prove this con- 

 clusion, they do not even suggest it. 



° In published writings Drieseh uses language 

 which seems to express a yet more definite repudi- 

 ation of wholesale experimental indeterminism. 

 Thus in Die Biologic als selbstdndige Grundwis- 



