MODERN THOUGHT 147 



" The Origin of Species " with its principle of natural selection, its 

 preservation of useful qualities, the influence of environment and 

 heredity, gave the genetic theory strong support. The views presented 

 by its illustrious author were set forth with such clearness and de- 

 fended with such wealth of illustration as to make their rejection a 

 matter of great difficulty. Even those who were most hostile recognized 

 their importance as well as their revolutionary character. It was evi- 

 dent to nearly every scientific man that henceforth the world could not 

 be explained upon morphological theories alone, and that some such 

 principle as that of natural selection must be presupposed in order to 

 explain the facts which in almost every department of scientific re- 

 search were daily coming to light. Natural selection has been defined 

 as " that process in life, automatic in its nature and action by which in 

 the struggle for existence useful differences are preserved and those 

 which are not useful are destroyed." It is under the operation of this 

 principle Spencer believed, and sought to show, that species are formed 

 and the various manifestations of life accounted for. Those who ac- 

 cepted Mr. Spencer's theories in full, with few exceptions, accounted 

 for the origin and evolution of the universe on purely mechanical prin- 

 ciples. 



But the questions as to life itself, its nature and its origin, were 

 not on this evolutionary theory fully answered. Granting that the 

 lowest forms of life are connected with the cell, that life is manifested 

 in its structure and through its growth, even on the assumption that 

 matter and energy only exist, the question can not be pushed aside. 

 Whence is the energy which brings life into matter, organizes it and 

 imparts to it the power or ability under the laws of evolution to create, 

 perfect and continue at pleasure, the forms in which it chooses to ap- 

 pear? Logically the genetic theory must explain the origin and con- 

 tinuance of life on mechanical principles alone. A theory in sharp 

 contrast to the genetic or evolutionary theory, which for many minds 

 reduces life to a mechanical process, is what Mr. Merz calls the vital- 

 istic theory. This theory is becoming more and more prominent with 

 the increasing interest in the study of biology. What life is, what is its 

 origin, what are its processes, are questions to which as yet completely 

 satisfactory answers have not been returned. Bichot (1771-1802) de- 

 fined life as the " totality of functions which resist death," a definition 

 which gives little information as to the nature of life, or its origin. 

 Claude Bernard (1813-78) wrote "life is the struggle of living forces 

 against the non-living." Since the publication of Darwin's book on 

 " The Origin of Species," or more exactly since 1866, a tendency is to 

 be noted which seeks to establish parallelisms between processes in 

 organic and inorganic bodies. Lavoisier was one of the first to study 

 life from a chemical point of view, and to explain respiration, nutri- 

 tion and the generation of animal heat as a form of combustion. In 



