SCIENCE AT THE MEDIEVAL UNIVERSITIES 449 



science, his authority being looked upon as so great that men did not 

 think for themselves but accepted his assertions. Smaller men are 

 always prone to do this, and indeed it constitutes one of the diflBculties 

 in the way of advance in scientific knowledge, as Roger Bacon himself 

 pointed out. 



These are the sort of expressions that are to be expected from Friar 

 Bacon from what we know of other parts of his work. His " Opus 

 Tertium " was written at the request of Pope Clement IV., because the 

 Pope had heard many interesting accounts of what the great thirteenth- 

 century teacher and experimenter was doing at the University of 

 Oxford, and wished to leam for himself the details of his work. 

 Bacon starts out with the principle that there are four grounds of 

 human ignorance. These are, "first, trust in inadequate authority; 

 second, that force of custom which leads men to accept without properly 

 questioning what has been accepted before their time ; third, the placing 

 of confidence in the assertions of the inexperienced; and fourth, the 

 hiding of one's own ignorance behind the parade of superficial knowl- 

 edge, so that we are afraid to say I do not know." Professor Henry 

 Morley, a careful student of Bacon's writings, said with regard to these 

 expressions of Bacon : 



No part of that ground has yet been cut away from beneath the feet of 

 students, although six centuries have passed. We still make sheep-walks of 

 second, third and fourth, and fiftieth hand references to authority; still we 

 are the slaves of habit, still we are found following too frequently the untaught 

 crowd, still we flinch from the righteous and wholesome phrase " I do not 

 know " and acquiesce actively in the opinion of others that we know what we 

 appear to know. 



In his " Opus Majus " Bacon had previously given abundant evi- 

 dence of his respect for the experimental method. There is a section 

 of this work which bears the title Scientia Experimentalis. In this 

 Bacon affirms that "without experiment nothing can be adequately 

 known. An argument may prove the correctness of a theory, but does 

 not give the certitude necessary to remove all doubt, nor will the mind 

 repose in the clear view of truth imless it finds its way by means of 

 experiment." To this he later added in his " Opus Tertium " : " The 

 strongest argument proves nothing so long as the conclusions are not 

 verified by experience. Experimental science is the queen of sciences, 

 and the goal of all speculation." 



It is no wonder that Dr. Whewell in his " History of the Inductive 

 Sciences" should have been unstinted in his praise of Roger Bacon's 

 work and writings. In a well-known passage he says of the " Opus 

 Majus": 



Roger Bacon's " Opus Majus " is the encyclopedia and " Novum Organon " 

 of the thirteenth century, a work equally wonderful with r^ard to its wonder- 

 ful scheme and to the special treatises by which the outlines of the plans are 



VOL. LXXVIII-— 31. 



