12 THE SCIENCE OF LIFE. 



quite unsatisfactory. That there are differences between 

 the living and the non-living will only be denied by the 

 most thorough partisans of Monism. These differences 

 depend on something in the living which is absent from 

 the non-living. In common parlance we call it life, or 

 life-force. Such a life-force is as necessary to Biology as 

 gravitation is to Physics, or light to Optics. 



Writers who avoid Dualism, or who acknowledge 

 antagonism to it, have not been able to give a clear 

 definition of life. 



Bichat defines life as " the sum of the functions by 

 which death is resisted." This is but saying that life 

 and death are opposite states. 



Dr. W. B. Carpenter, although believing in the difference 

 between mind and matter, speaks of life as " the condi- 

 tion of a being which exhibits vital actions ; " which is but 

 another mode of stating that life is a condition or state 

 of living. 



Coleridge considered life as synonymous with " indi- 

 viduation." This is equivalent to separate existence, 

 and includes metals, and stones, and all non-living things. 



Herbert Spencer defines life as "the continuous adjust- 

 ment of internal relations to external relations." This 

 definition will apply to a boiling tea-kettle, a steam- 

 engine, or a burning candle, as well as to a living thing. 



Haeckel declares " that all natural bodies which are 

 known to us are equally animated, and that the distinc- 

 tion which has been made between animate and inani- 

 mate bodies does not exist." This exceedingly bold and 

 strange statement is rendered necessary by the logical 

 demands of the Monistic philosophy. In a subsequent 



