PHILOSOPHICAL ASPECT OF EVOLUTION. 455 



and Ontogeny which have been brought forward, a mass 

 of suggestive thoughts and reflections which cannot fail 

 of their effect on the further development of the philo- 

 sophical study of the universe. Neither can it be doubted 

 that these facts, if properly weighed, and judged without pre- 

 judice, will lead to the decisive victory of that philosophical 

 tendency, which we distinguish, briefly, as monistic or 

 mechanical, in distinction from the dualistic or teleological, 

 on which most philosophical systems of ancient, mediseval, 

 and modern times are based. This mechanical, or monistic 

 philosophy, asserts that everywhere the phenomena of 

 human life, as well as those of external nature, are under 

 the control of fixed and unalterable laws, that there is 

 everywhere a necessary causal connection between pheno- 

 mena, and that, accordingly, the whole knowable universe 

 forms one undivided whole, a " monon." It further asserts, 

 that all phenomena are produced by mechanical causes 

 {causae ejjficientes), not by pre-arranged, purposive causes 

 (causce finales). Hence there is no such thing as "free- 

 will " in the usual sense. On the contrary, in the light of 

 this monistic conception of nature, even those phenomena 

 which we have been accustomed to regard as most free and 

 independent, the expressions of the human will, appear as 

 subject to fixed laws as any other natural phenomenon 

 Indeed, each unprejudiced and searching test applied to the 

 action of our " free-will ' ! shows that the latter is never 

 really free, but is always determined by previous causal 

 conditions, which are eventually referable either to Heredity 

 or to Adaptation. Accordingly, we cannot assent to the 

 popular distinction between nature and spirit. Spirit 

 exists everywhere in nature, and we know of no spirit out- 



