ON THE VITALISTIC VIEW OF NATURE. 381 



content itself with the known and the knowable. Prac- 

 tice is placed face to face with the unknown and the 

 unknowable. 1 Thus the question will again and again 

 be asked, " What is life ? " And for the benefit or 

 injury of mankind theories will exist which profess to 

 handle this delicate problem successfully, even as 

 weather-prophets will always exist though the necessary 

 knowledge for accurate prediction is still wanting. 



One of the first in time and eminence in the course of 

 the nineteenth century to whom we are indebted, not 



Practice 

 urges the 

 question : 

 What is 

 Life? 



1 See what Theod. Bischoff, one 

 of the first and foremost German 

 anatomists of the new school, says 

 in his Eloge of Liebig (Miinchen, 

 1874), p. 60. " Inorganic science is 

 not any way induced and is much 

 less obliged to forsake the road 

 from the known to the unknown. 

 But what would have been the 

 result, what would still be the 

 result, if, in all our researches into 

 organised nature, and yet more in 

 all our actions which have refer- 

 ence to our state of health or ill- 

 health, we had proceeded, or were 

 now to proceed, only from data 

 firmly established as to cause and 

 connection ? Could we then so much 

 as take a morsel into our mouths 

 or treat a cold otherwise than with 

 fear and trembling ? Physiologists 

 and doctors have surely always been 

 ready to proceed according to the 

 methods of exact science so far as 

 this was developed. But so long as 

 this gave but a stone instead of 

 bread, acceptance could not be 

 thought of ; necessity compelled 

 us to make some attempt towards 

 the solution of questions, to invent 

 some language in order to gain an 

 understanding ; and through this 

 frequently an erroneous procedure 

 has arisen which outlives the means 

 for its correction." "Physiology," 



Bichat. 



says Du Bois-Reymond (Eloge of 

 Joh. Miiller, ' Reden,' vol. ii. p. 

 199), "is the only science in which 

 one is obliged to speak about things 

 which one does not know. Chem- 

 istry need not treat of unknown 

 compounds, nor physics of undis- 

 covered forces ; botany and zoology 

 do not mind what kind of animals 

 may still move about unknown 

 among unknown vegetation in un- 

 explored regions. But in physi- 

 ology, even if we confine ourselves 

 to man, a definite number of things 

 is given which must be dealt with. 

 The spleen, the thyroid gland, the 

 thymus, the suprarenal capsules ; 

 many parts of the brain, ganglia, 

 nerves, the labyrinth of the ear all 

 these are there, and must, according 

 to the customary view, be there for 

 something. Manifold suppositions 

 as to the functions of these parts, 

 seemingly supported or invalidated 

 by pathological experience, have 

 put in the place of absolute dark- 

 ness a twilight which is richer in 

 delusions though not in certainty. 

 The expounder of our science is 

 obliged to lead his pupils through 

 this twilight on an anxious path, 

 and then meet in return with that 

 discouragement which really is 

 owing to the subject itself." 



