380 SCIENTIFIC THOUGHT. 



that the answer which we may give to them is of no 

 scientific importance and of no scientific value. The 

 question, " What is electricity ? What is the ether ? " 

 cannot yet be answered ; nevertheless the sciences which 

 deal with the properties of the ether or of electrical 

 bodies are advancing daily. So also we are told 

 does the science of biology progress, even though we 

 leave the question " What is life ? " unanswered. This 

 would be a tenable position if the living organism were 

 like an electrical or an optical apparatus, constructed by 

 man himself with the modicum of knowledge which he 

 possesses. But the living organism, the eye that can 

 see or the nervous system that is in action, or even the 

 smallest " autonomous " cell, visible only with the micro- 

 scope, are each an apparatus constructed by nature with 

 the employment of all the intricate agencies which are 

 at her command. In dealing with such an apparatus, 

 we are again and again tempted to ask, " What is life ? 

 On what does the normal and healthy co-operation of 

 all parts in the living organism depend ? In what does 

 it consist ? " Fragmentary knowledge may be well 

 enough so far as it goes, but every medical practitioner 

 must painfully feel it to be altogether insufficient. 

 Where practical interests are involved we cannot in- 

 definitely postpone our answers. Science can wait and 



physiques elle ne peut exercer 

 aucune influence sur elles. II faut 

 done ici separer le monde meta- 

 physique du monde physique phe- 

 nome'nal qui lui sert de base, mais 

 qui n'a rien a lui emprunter. . . . 

 En rdsume, si nous pouvoiis definir 

 la vie a 1'aide d'une conception 



pas moins vrai que les forces me- 

 caniques, physiques, et chimiques, 

 sont seules les agents effectifs de 

 1'orgauisme vivant, et que la physio- 

 logiste ne peut avoir a tenir compte 

 que de leur action. Nous dirons 

 avec Descartes : on pense meta- 

 physiquement, mais on vit et on 



mdtaphysique spe"ciale, il n'en reste agit physiquement." 



