428 PHYSIOLOGY 



shall be done mainly by those whose training has been received 

 in the observational sciences, it seems inevitable that the specialist 

 in physiology must also enter the field. Chemical and physical 

 methods are clearly adapted to the study of these problems, for in 

 the end we expect to find the scientific explanation of growth and 

 development in the physical and chemical properties of living 

 matter. The subject is as truly a part of physiology as the pro- 

 cesses of secretion and nutrition. In the current literature upon 

 the subject there is at present a freedom in the formation of hypo- 

 theses and a reliance upon the virtues of the syllogism which tend 

 to bring it into sympathetic relations with philosophy rather than 

 with physiology. But as the store of observed and demonstrable 

 data is increased, the boundary-line between the probable and the 

 improbable will be more sharply drawn, and more objective methods 

 and less ambiguous theories will mark the development of the subject 

 along experimental lines. 



In the strictly physiological literature of the past century, a char- 

 acteristic feature has been the absence of philosophical speculation. 

 Although the physiologists have been concerned most directly 

 with the problems of life, they, of all the biological family, have 

 been least productive in the philosophical discussions that have 

 prevailed during this period. Those who were most conspicuous in 

 laying the foundation of our exact knowledge followed upon an age 

 of free speculation, and therefore, as it were by protest against 

 this tendency, devoted themselves to an empirical study of the sub- 

 ject, following the admonition of Harvey mentioned above; of 

 Hunter, whose advice was, "Don't think, try;" and of Magendie, 

 whose guiding principle of work was similarly expressed. 



At the present time there are indications that the workers in 

 physiology are dissatisfied with this cautious attitude. There 

 seems to be a reaction against the purely empirical procedure, and 

 a demand for the discussion of the underlying philosophical prin- 

 ciples. This tendency, in fact, has seemed to affect all of the ex- 

 perimental sciences. "All sciences," says Ostwald, 1 "are tending 

 to be philosophical;" and he and others see in this fact an indica- 

 tion of the approach of an era of synthesis in science, a beginning 

 of the unification of all the widely separated specialties toward a 

 common end. Others will perhaps view this tendency with alarm, 

 and imagine that history is repeating itself; that after a century 

 of objective experimentation the restless mind of man is reverting 

 to the speculative methods of the eighteenth century and attempt- 

 ing after the manner of other days to reach by a shorter path the 

 final goal of an understanding of the mysteries of the universe. 

 Truly, when one examines the results of this recent tendency, he 



1 Loc. cit. 



