October 4, 1912] 



SCIENCE 



435. 



this profound way. Thus if his point of view 

 is accepted my paper quite lacks a raison 

 d'etre; I was combating windmills. 



In my former paper I made no attempt to 

 show that Driesch's views were of the char- 

 acter that I set forth, because it seemed to me 

 (and still seems to me) that he had stated, in 

 his published works as fully and unequivocally 

 as it is possible in words, that they are of that 

 character; and that, moreover, his whole argu- 

 ment loses its coherence and becomes incom- 

 prehensible if they are not.^ I therefore did 

 not expect any one who had made a careful 

 examination of Driesch's " Science and Phi- 

 losophy of the Organism" to question this. 



Since, however, it has been questioned by 

 one so competent as Lovejoy, with the intima- 

 tion, as quoted above, that my own scrutiny 

 had not been sufficiently close, it is of interest 

 to learn Driesch's ovTn opinion on this point, 

 when the matter at issue is put explicitly be- 

 fore him. I quote, by permission, from letters 

 received from Dr. Driesch: 



You are quite right in saying ' ' the biologist 

 can not from a knowledge of the total physical 

 configuration predict what will happen even after 

 he has observed it. ' ' This is indeed a consequence 

 of my vitalism and I am very glad to see that 

 you fully appreciate it. 



I reject absolute indeterminism but accept ex- 

 perimental indeterminism. 



In other words: A complete knowledge of all 

 physico-chemical things and relations (including 

 possible relations) of a given system at the time 

 t gives not a complete characteristic of that 

 system in the case that it is a living system. 



' Driesch 's argument is one by exclusion, run- 

 ning essentially as follows: Since there are no 

 diversities in the physical conditions that explain 

 satisfactorily the diverse results in certain dif- 

 ferent eases, and since we must hold to deter- 

 minism, it follows that there must be something 

 non-physical (i. e., entelechy) to account for the 

 diversities in results. It appears to me that the 

 failure to correctly apprehend Driesch's argu- 

 ment is what causes Lovejoy to intimate fre- 

 quently that the entelechy concept is superfluous 

 in Driesch's vitalism; merely "dragged into the 

 situation," as he expresses it. Without entelechy 

 a yawning hiatus is left in Driesch's system; it 

 is all that saves him from absolute indeterminism. 



Or: Two systems, absolutely identical in every 

 physico-chemical respect, may behave differently 

 under absolutely identical conditions, in case that 

 the systems are living systems. 



For: the specificity of a certain entelechy is., 

 among the complete characteristics of a living 

 organism, and about this entelechy knowledge of- 

 physico-chemical things and relations teaches. 

 nothing. 



My short formula about the matter in question 

 is: No absolute, but "experimental" indeter- 

 minism. 



Dr. Driesch's statements of the matter are ■ 

 then fuUy as strong as my own. If he under- 

 stands his own philosophy, it therefore appears 

 to me that the further reasoning in my former- 

 paper was quite justified, and is entitled to 

 the careful consideration of any others who 

 have leaned toward Driesch's. vitalism without , 

 realizing that it means experimental indeter- 

 minism. 



H. S. Jennings 



ZOOLOGICAL NOMENCLATURE 



To THE Editor of Science: In Science for- 

 August 9, my esteemed friend Dr. Kingsley, 

 makes a plea for various exceptions to the 

 rule of priority in names of animals and to 

 other rules which have been adopted by the- 

 Commission on N^omenclature of the Inter- 

 national Zoological Congress. 



It is no doubt exasperating to many zool- 

 ogists who have to use only a few systematic ■ 

 names in their work and then at long intervals, 

 to find that in these intervals older names, . 

 carelessly or ignorantly neglected in the past, 

 have risen to take their, places. It is also ex- 

 asperating to professional taxonomists and . 

 students of geographic and other relations of 

 species, to be told that, their efforts to bring 

 past confusion into order shall be set aside 

 whenever these efforts, discommode workers in 

 other fields of zoology, who for the most part , 

 neither know nor- care for tbe part accurate 

 bookkeeping must play in the study of system- 

 atic zoology and botany. 



Taxonomy with geographical and geological; 

 distribution, constit^it^s, a^. science by itself,. 



