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belief on authority is primarily and mainly an assent to individual 

 truths of fact, irrespective of the laws embodied in these latter. 

 But from those points of difference it must not be inferred that 

 &quot; scientific &quot; knowledge, simply as such, is either more certain or 

 more important than knowledge of facts on human authority. 

 It would be a serious mistake to think that it is. From the 

 general standpoint of philosophy, that is, from the standpoint of 

 man s general outlook on the world and life, and on his own 

 nature, destiny, and place in the universe, there are individual 

 historical facts that are incomparably more momentous than whole 

 bodies of &quot; scientific &quot; knowledge. The great group of facts com 

 prised in the establishment of the Christian religion nearly two 

 thousand years ago, is bound up with truths of greater import to 

 men than, for instance, all the laws of the science of mechanics. 

 &quot; Scientific &quot; knowledge is not, therefore, merely as such, more 

 important than the knowledge known as &quot; belief&quot;. Neither is it 

 always and necessarily superior to the latter from the point of view 

 of certitude, or firmness of assent. The character of the mental 

 state, as revealed in consciousness, is undoubtedly not the same 

 when I assent to the truth that &quot; The three angles of a triangle are 

 equal to two right angles&quot; as when I believe that &quot; The Liffey is 

 not flowing backwards to-day,&quot; or that &quot; Great Britain is an 

 island &quot; ; but my assent is &quot; firm &quot; or &quot; certain &quot; in all three cases. 



Human testimony can never, of course, be an ultimate motive 

 of certain assent. Such assent, given on the authority of such 

 testimony, must be always preceded by two other assents to 

 the two judgments, &quot; My informant is not deceived,&quot; and &quot; He is 

 not deceiving me &quot;. Now, if we assent to these judgments, or 

 either of them, on the authority of some other testimony, the 

 same two conditions have to be verified in regard to this latter 

 testimony. Hence, under pain of being involved in an endless 

 regress, we must ultimately have intrinsic evidence for the presence 

 of the two requisite qualifications in some testimony of the series. 



Furthermore, in matters of science, where the truth can be 

 ascertained by rational investigation into the intrinsic evidence, 

 the right and proper certitude to seek is scientific certitude. But 

 the authority of a teacher or master is not a motive that can 

 produce certitude of this kind. It is an extrinsic motive, which 

 can produce certitude of belief ; and hence we cannot appeal to it 

 in scientific research. In science, where our aim is to reach scientific 

 certitude, such an appeal is the weakest of all arguments. This 



