ADDRESS OF 



may be hammered into an entirely new shape. But however com- 

 pletely it may stand the fire, it maintains its position as a scientific 

 theory only by being always in the field ready to challenge every 

 new comer, and to meet the fire of every fact which seems to mili- 

 tate against it. A countless host of theories have thus been 

 demolished and forgotten with the advance of knowledge, but those 

 which remain, having stood the fire of generations, can show us a 

 guarantee of their truthfulness which would not be possible under 

 any other plan of dealing with them. 



As a consequence of this way of viewing theories, the scientific 

 man recognizes no such attribute as orthodoxy in his doctrines. 

 There is nothing at all which he says you must believe to be true 

 as a condition of scientific recognition. There may, indeed, be 

 many propositions to doubt which would indicate extraordinary 

 incredulity, or down-right folly, or even insanity, and he might, 

 therefore, regard a skeptic as possessing a pitiful feeblenesss of 

 intellect, and, in consequence, refuse to listen to him ; but he 

 would refuse, not because the man disbelieved something which 

 was undoubtedly true, but because he was not worth listening to. 

 Perhaps the point which I am striving to make clear may be most 

 readily grasped by the reflection that science offers its highest 

 , rewards to him who will overthrow and supplant its best estab- 

 lished and most widely received theories. Thus, the names of the 

 men who disproved the theory of epicj^cles in astronomy, and the 

 doctrine of phlogiston in chemistry, occupy the most honorable 

 positions in the history of science. Of course, no such thing as 

 authority in science has anything more than a provisional recogni- 

 tion. If a man of good repute says that he has investigated a 

 certain subject and reached a certain result, the latter may be ac- 

 cepted on his authority, in the absence of other evidence. But 

 this gives no reason at all why anyone else should not reach a 

 different result, and it would be no argument at all to cite the 

 mere authority of the first against the second. In case of a dis- 

 crepancy of this kind, the whole question would have to be reinves- 

 tigated. The dictum, "It is written," has no terror whatever for 

 the investigator of nature ; he can recognize no authority for any 

 feature in the course of nature, except nature herself as he sees 

 her. 



These principles are of so much importance in the philosophy 

 of science, that I may be pardoned for viewing them in yet another 



