INTRODUCTION 



1. Threefold division of biological science. 2. Special objects of physiology. 

 3. Materialism, neo- vitalism, Ostwald's energetic monism, Mach's psychical monism, 

 pragmatic pluralism. 4. Physiology of the cell ; general and comparative 

 physiology ; human physiology. Bibliography. 



THE remarkable development of Physiology during the nine- 

 teenth century justifies us in regarding it as one of the most 

 modern sciences ; yet its origin is very ancient, and may be 

 traced back to the first flashes of philosophic thought. Through- 

 out the classical world, however, with few exceptions, the term 

 Physiology (according to its etymological signification) connotes 

 the philosophic study of Nature in general, i.e. it includes the 

 phenomena, not merely of living nature, but of inanimate nature 

 as well. 



During the Middle Ages, again, until the Renaissance, the 

 Science of Life is confounded with Philosophy, with Natural 

 History, with Medicine in general, and in particular with Anatomy. 



In the second half of the eighteenth century the immense 

 progress made in the vast field of Natural History (so-called) 

 involved a corresponding division of labour. Intimate relations 

 obtain between mineralogy, geology, and physical geography. 

 These are complementary and reciprocal subjects, which are all 

 included among the inorganic natural sciences. Most intimate, 

 too, are the links connecting botany and zoology : " Between 

 plants and animals," as was happily said by Buffon, " there are 

 more common properties than real differences." Between dead and 

 living nature, however, the gap is far wider, the differences more 

 essential, and the study of the one may be undertaken independent 

 of the other. 



At the commencement of the last century two eminent natural- 

 ists, Lamarck in France, and Treviranus in Germany, created the 

 word Biology, and applied it in the first instance to designate 

 the complex of closely related sciences which covers the phenomena 

 observed in living beings in general, i.e. in plants, animals, and 

 man. 



VOL. I 1 B 



