REFLECTIONS AND CONCLUSION. 395 



those who taught and speculated three centuries 

 ago, we need not be surprised at the many strange 

 things they said and did. We see in their opinions 

 and conduct but a reflex of what is always observed 

 in the progress of knowledge and in the dissipation 

 of ignorance. The much-talked-of warfare between 

 science and religion is something that does not exist. 

 The warfare is between truth and error, between sci- 

 ence and theory. In Galileo's case, as we have seen, 

 it was Copernicanism versus Aristotelianism ; a priori 

 reasoning against observation and experiment ; the 

 syllogism against the telescope. 



Conservatism in Science. 



And more than this. The same objections that 

 were brought against Galileo and heliocentrism, were 

 urged against Laplace and the nebular hypothesis ; 

 against Joule, Mayer, Faraday, Liebig, Carpenter 

 and Helmholtz, on account of their demonstrations 

 of the grand doctrine of the conservation and corre- 

 lation of the various physical forces. The truth is, 

 men are loath to give up a pet theory, especially 

 when they are once committed to it, and when the 

 shadow of a great name gives to it an air of certainty, 

 if not of infallibility. As a result of this tenacious- 

 ness of opinion, and of a conservatism which was far 

 more marked formerly than it is at present, truth 

 advances slowly and science is obliged to contest 

 every step forward. For this reason the enemy of 

 science has not been religion, as is so often declared, 

 but science itself, or what for the time was accepted 



