July 22, 1898.] 



SCIENCE. 



91 



ideal unity, two steps ; I mean the abstract 

 difference of the kej'S and the abstract iden- 

 tity of the pianist. And Nageli's theory, 

 like all other theories of ontogeny, exists 

 only in order to insert those two steps." 



The author then proceeds to a considera- 

 tion of the agent as a quasi-psychical prin- 

 ciple, and as illustrating all doctrines of the 

 class he chooses the theory of Bunge as set 

 forth in his essay on Vitalism and Mechan- 

 ism, in which there is laid down the familiar 

 distinction between physical and chemical 

 processes, on the one hand, and vital pro- 

 cesses, on the other. " The former as me- 

 chanical are set over against the latter as in 

 some way not mechanical, but as free from reci- 

 procity and as conditioned only by ends. * 



* * But we have no reason for excepting 

 psychical processes from that form under 

 which we include the rest of the organism. 

 Thinking is not miracle any more than 

 ' cerebration ' is miracle, and as a process it 

 is as much in bondage to necessity as any- 

 thing else is. * * * ^lueprnpogefulness of the 

 organic differences is that which has to be 

 explained, but the two kinds of processes 

 which are here distinguished do not differ 

 in respect of that matter. Both are, if both 

 exist, equally purposive in fact and equally 

 mechanical in derivation. And all that the 

 theory seems to do is to add to one set of 

 processes another set which does not at all 

 help us in the explanation of the former. * * 



* An intelligence is, indeed, an identity in 

 diiference, and it is perhaps natural that we 

 should seek to insert such an intelligence 

 into the organism as the agent of its iden- 

 tity. But an intelligence is the unity of its 

 own differences — its own states ; there is 

 no conceivable sense in which it should be 

 unity for the parts of the body." 



In conclusion, the author examines the 

 various theories of the agent in their rela- 

 tion to fact and as to their characteristics 

 as a method. As to their relation to fact 

 he attempts to apply these theories to the 



structure and functions of the Protozoa. 

 What is the inner secret of the remarkable 

 outer differences which are found in this 

 group ? " The agent here is of no avail, for 

 you cannot divide up these creatures into 

 separate cooperating cells nor regard their 

 qualities as carried by vehicles. You can- 

 not, in short, in their case delude yourself 

 with the belief that individuality in organ- 

 isms is a vain show due to the external 

 action of an agent or system of agents upon 

 the passive material which is known to us 

 in research. * * * I believe I am right in 

 saying that no exj)lanatio7i of the immediate 

 existence of any morphological element has ever 

 been made. And this fact, veiled in the case 

 of the Metazoa, because in their case an 

 external significance for the structure can 

 so easily be found or feigned, lies open to 

 us chiefly in the case of the unicellular 

 animals, in which we are at once forced to 

 see that form must have its rationale and to 

 confess that this rationale is hidden from us." 



As to the general characteristics of the 

 hypothetical agents the author observes: 

 (1) that they are not known and have not 

 been observed ; (2) they are a scaffolding 

 for the synthesis of abstract sciences ; (3) 

 they are alogical, and (4) they are unknow- 

 able. " In all these characteristics of the 

 agent there is but one endeavor on the part 

 of the theorists ; it is to find an expression 

 for the unity of the organism. But the 

 method seems to me to be so riddled with 

 contradictions as soon as it is taken seri- 

 ously, and to be in any case so formal and 

 inefficient, that we had better leave the 

 whole problem alone than solve it by the 

 empty doctrine of the independence of or- 

 ganic qualities and by the empty hypothesis 

 of the anthropomorphic agent." 



III. The third postulate is the basis for 

 all theories of adaptation, whether they be 

 those of evolution or of design. It pro- 

 ceeds from the assumption that " everything 

 organic exists only by reason of, and is to 



