PHYSIOLOGY Ixxi 



this way, or that way, or the other way : hence the only 

 remaining conceivable explanation must be the true one." 

 And then ensues some ridiculous theory, always depending on 

 a new, mysterious, and invisible agency : it has to be invisible 

 of course, since no power of microscope or balance can dis- 

 cover it. Hence we get spirits, animal spirits, souls, subtle 

 fluids, vital forces and other " monstrous products begotten 

 by the imagination," as Lamarck himself well calls them 

 elsewhere. These agencies are in turn relegated to the 

 sphere of superstition, as science grows. Lamarck claimed 

 the support of science for the existence of subtle invisible 

 fluids : science has entirely disposed of them. The nervous 

 impulse is still not properly explained : and doubtless until 

 it is, it will continue to be regarded as a suitable playground 

 for spiritualistic fancies and desires. But year by year 

 these phantoms find it harder to discover any dark and 

 unexplored corners of science, where they may obtain a 

 momentary respite from the ever-advancing tide of material- 

 istic knowledge. 



To do Lamarck justice, his theory was not so outrageous 

 as is that of the modern vitalists. He invoked a factor, 

 which he imagined (wrongly no doubt) to be equally instru- 

 mental in the inorganic world. His subtle fluid was not 

 invented ad hoc ; it was recognised as a real existence by 

 many physicists of his time. But the modern vitalists 

 invent a factor that is wholly and unutterably new to science, 

 and to every branch of knowledge or history. Their plunge 

 into the unknown is far wilder and more furious than his. 

 Their search for a hypothesis has led them to the most remote 

 regions of primitive superstition ; it has led them to invent 

 a factor out of hand for the purposes of their own theorisa- 

 tion — a factor unknown to any branch of science, a factor 

 unrecorded in any trustworthy history, a factor which breaks 

 down utterly and immediately under analysis, and lastly a 

 factor which, so far from explaining the facts it is supposed 

 to explain, throws over them an impenetrable cloud of 

 mystery ami obscurity. 



