No. 606] 



BL<)L(n.l( M KXK.MA: 



349 



make them appear as specific cxi)lanatioiis should he avoided. 



Tliere are a number of principles of scientific inetli- 

 odology whicli have a bearing upon criticisms of this 

 sort. In the first place such a statement as that "life is 

 motion" would have value at a time when the connection 

 between these two ideas had not been noted, or had l>een 

 underemphasized to such an extent that eminent scien- 

 tists were bemoaning the inability of the human mind to 

 account for properties of life which the most sui)erncial 

 examination would show to be identical with those of 

 motion. From my own point of view the ])7-(>position that 

 "life is determined by specific catalysis" appears to be 

 somewhat of the nature of a truism, indeed so much so 

 that even if we had no direct evidence for the existence 

 of enzyme action, we should be forced to invent the con- 

 ception to account for the most general |)roperties of liv- 

 ing systems. It seems to me that this is exactly what a 

 considerable number of biolou'ists actually liavo ilone, and 

 the only important iti'dv in tlicii' tliiiikinu' lir- in the a]>- 

 plication to the conccpl n!' naiiu- a- • • 



"detei'minant, " "niiii cliai-aclcr." • ' r.)niian\ (' factor." 

 ''Eh-mvuiaynr<,mnswr -■rhiu nlair ny • • cutdechy. " 

 Tlil^ vvvov. lioNv.'vei'. 1< fatal to pivLiT.--. a^ it iiuilti].lies 

 tci'iiiinnloux aiul (lrla> ^ t lie ^^ntM. ^1^ mT actual iJea- which 

 is the u-(.al s.-Initili.- cii.l.'av.»i-. 



Furtlii fni(»i-c, it i- not Wnv tliat tlu' estabii.-limcnt of a 

 general i)riMcIpI(' lUMH-^ilatfs an cxamiiiati.m of all of 

 the concT-ctc details ot' sped lie systfin^. IT this were so, 

 none of the futnlatnetital law^ of ine.-hairu-. Mi.-h the 

 first and mvou.I law^ of eiiei-etir. or 1 ramilloii'. prin- 

 ciple, WOUI.I po^^, aiix lio-Mlity. Mllee tbe> are .lerixed 

 from a study of what may be ealle.l the "eiiti'ance and 

 exit" properties of im cliaiiiea! -\ -teiii-, \\ itlioiil reference 

 to their exact content-. It to l»e adinitte.l. of course, 

 that we can not rest eoiiteiit witli this kin,! ,,f knowledge, 

 and that ]trin('ii)les of tlii> sort I'eeeive comitlete elucida- 



