PREFACE TO THE AMERICAN EDITION. 



I HAVE endeavored, in the following essay upon Micro-organ- 

 isms, to show that psychological phenomena begin among the very 

 lowest classes of beings; they are met with in every form of life 

 from the simplest cellule to the most complicated organism. It is 

 they that are the essential phenomena of life, inherent in all pro- 

 toplasm. 



We admit, accordingly, the existence of a vitalism, that is to 

 say, of an aggregate of properties which properly pertain to living 

 matter and which are never found in inanimate substances. Among 

 these properties of life we classify psychological phenomena. 



Vitalism, it is unnecessary to say, has nothing in common with 

 the doctrine upheld by the School of Montpellier. The principle 

 here involved has nothing to do with properties and forces that are 

 superadded to living matter; it concerns the properties that are in- 

 herent in it the properties that characterize life. 



The modern opponents of vitalism seek to confute the theory 

 by attempting to explain all phenomena of life from physico-chem- 

 ical forces. They maintain that according as physiology advances 

 the tendency is to relegate all phenomena nominally physiological 

 into the domain of physics and chemistry; and that it would be 

 only a question of time, if as yet they had not succeeded in dem- 

 onstrating that every vital process is founded upon mechanical 

 phenomena. 



In a recent treatise upon "Vitalism and Mechanism,"* M. 

 Bunge, professor of physiology at Basel, has shown that the his- 

 tory of physiology disproves these hypotheses. The more closely 



* G. Bunge, Vitalismus und Meehaitisinus, Bin Vortrag, 1886. 



