DEVELOPMENT OF PLANT PHYSIOLOGY 117 



identifies vital force with the will, he can offer nothing further to 

 the scientist. 



As often as philosophy has disturbed natural science, as did the 

 so-called nature philosophy in the period of Schelling, has the sound 

 thought of the scientist always repaired the damage which has 

 been done to our science by the misuse of the human mental power. 



The marked philosophical movement of to-day in the natural sci- 

 ences revolves chiefly about the questions of the origin of life, about 

 the vital force, about the alternative mechanism or vitalism, and 

 about the propriety of a teleological conception of nature. 



The further our knowledge of facts extends, the greater becomes 

 the gulf between the lifeless and the dead. Schleiden would have it 

 that the }^easts arise spontaneously from the nutritive fluids; even 

 after the epoch-making researches of Pasteur the attempt was made 

 to show that bacteria arise spontaneously. But this is all past, and 

 there is no fact to support the idea that the living can arise from 

 the non-living. A new support for the correctness of this view is 

 to be found in the conception, supported by an immense amount of 

 evidence, that in the organism, also, the organized or living elements 

 can arise only from the living. 1 



The specific philosophers have offered us nothing on the question 

 of origins. For when Kant, with a far-seeing eye, expressed the view 

 that the living may not arise from the non-living, it was the scientist 

 in him that spoke. When, on the other hand, Naegeli supported 

 the idea of generatio spontanea, arid, indeed, represented the view 

 that this continues without interruption (while the monists are 

 usually content with the once-for-all origin), this eminent man 

 denied the scientist in him, and descended to doctrinaire specula- 

 tion. So various is the human disposition that the great philosopher 

 Kant expressed himself on the question of primal origin for a whole 

 century, just as the scientist must at the present moment, while so 

 eminently a modern scientist as Naegeli took the position in this 

 matter not simply of a philosopher of the monist type, but rather 

 of a metaphysician. The arguments of E. von Hartmann that there 

 is now no generatio aequivoca, because, in view of the stability of both 

 organic kingdoms, this is no longer necessary, had obviously no effect 

 upon scientists. 



But the recent attempts of a prominent scientist to bring back the 

 problem into the field of physics and chemistry by making an analogy 

 between crystal formation in metastabile solutions with spontaneous 

 generation was only an intellectual idea without further consequence 

 in leading to a solution of the question. 2 



1 Wiesner, Die Elementarstruktur und das Wachstum der lebenden Substanz, Wien, 

 1892, p. 82 ff. 



2 Ostwald, Vorlesungen uber Natur philosophic, Leipzig, 1902, p. 345 ff. 



