140 Scientific basis of Good. 



That the same causes, acting under different con- 

 ditions, produce different and even opposite effects, is 

 a well-known scientific truth. The same heat of 

 summer which causes our foods to decay, promotes 

 the growth of plants in the soil! the same cold of 

 winter which increases the pain of bronchial affections, 

 and cuts short the lives of aged and infirm persons, 

 acts as a stimulant and a source of pleasure to the 

 young and healthy. We need not therefore be sur- 

 prised, that the same physical conditions and princi- 

 ples of nature, act as causes or conditions both of 

 what we term evil and what we term good. If, also 

 the theory of relativity in physical and mental action 

 is true, that change of impression is a necessary cause 

 or condition of consciousness, and that previous ex- 

 perience of pain increases the perception of pleasure, 

 we possess in that theory, as one of the general ideas 

 of science, a partial basis of morality. All these 

 -remarks tend to shew, that in order to obtain a truly 

 scientific view of the nature of man, and of man's 

 position and duties in the Universe, we must avoid 

 the errors caused by unconnected consciousness. 



Another great moral effect of the continual dis- 

 covery of new truth in science, is the gradual produc- 

 tion and diffusion of uniformity of belief, first amongst 

 scientific men, and then amongst the mass of man- 

 kind. This uniformity of belief is a necessary result 

 of the invariability of fact and law ; it does not 

 extend to scientific opinions, hypotheses or theories, 

 because they are not necessarily facts, and may be 



