THE DYNAMIC ELEMENT IN LIFE. H? 



due moisture and warmth are supplied. (Cf. Kerner's Nat. 

 Hist, of Plants, i, 51-2). Under what form has the vital 

 principle existed during these long intervals? It is a prin- 

 ciple of activity. In this case, then, the principle of activity 

 becomes inactive. But how can we conceive an inactive 

 activity? If it is a something which though inactive may 

 be rendered active when conditions favour, we are introduced 

 to the idea of a vital principle of which the vitality may 

 become latent, which is absurd. What shall we say of the 

 desiccated rotifer which for years has seemed to be nothing 

 more than a particle of dust, but which now, when water is 

 supplied, absorbs it, swells up, and resumes those ciliary 

 motions by which it draws in nutriment? Was the vital 

 principle elsewhere during these years of absolute quies- 

 cence? If so, why did it come back at the right moment? 

 Was it all along present in the rotifer though asleep? How 

 happened it then to awaken at the time when the supply of 

 water enabled the tissues to resume their functions? How 

 happened the physical agent to act not only on the material 

 substance of the rotifer, but also on this something which is 

 not a material substance but an immaterial source of activity ? 

 Evidently neither alternative is thinkable. 



Thus, the alleged vital principle exists in the minds of 

 those who allege it only as a verbal form, not as an idea; 

 since it is impossible to bring together in consciousness the 

 terms required to constitute an idea. It is not even " a fig- 

 ment of imagination," for that implies something imaginable, 

 but the supposed vital principle cannot even be imagined. 



36d. When, passing to the alternative, we propose to 

 regard life as inherent in the substances of the organisms 

 displaying it, we meet with difficulties different in kind but 

 scarcely less in degree. The processes which go on in living 

 things are incomprehensible as results of any physical actions 

 known to us. 



Consider one of the simplest that presented by an ordi- 



