THE PREDECESSORS OF COPERNICUS. 335 



to admit the presence of blanks in the experience of past centuries; 

 and also the presence of insights upon fundamental matters astonish- 

 ingly different in intensity and in quality from our own. The ex- 

 perience of the thirteenth century was handed onwards to succeeding 

 ages; it could be understood by the ages near to it; words continued 

 to mean in the fourteenth very nearly what they meant in the pre- 

 ceding century. But as ideas changed, the signs for ideas changed 

 with them; and we must be constantly on our guard lest we unthink- 

 ingly admit an old form as if it had the new meaning. 



Consider, for example, what astrology meant to Eoger Bacon and 

 what it means to us. He had no difficulty in reconciling the fateful 

 influence of the stars with a scheme of salvation for men possessed of 

 free-will. Words had different meanings to him and to us. His mind 

 was conscious of no conflict between his religion and his science. His 

 religion — that of the thirteenth century — is in absolute conflict with 

 our science — that of the twentieth. Let his one example stand as 

 a type of many that might be brought forward. 



In what follows we shall study the words of Roger Bacon, the 

 highest product of the thirteenth century.* His Opus Ma jus has 

 recently (1897) been admirably edited by Bridges. Bacon has there 

 expressed himself fully; and his century can be understood by im- 

 plications. For this reason — to recreate, as it were, the background 

 upon which the figure of Copernicus is projected, I have set down a 

 few sentences. The paragraphs chosen relate chiefly to science, in 

 which Bacon was far advanced, but enough is given of his views of 

 philosophy, theology and morals to assist our judgment of his time. 

 These extracts show what was possible to a man of the thirteenth cen- 

 tury; and Bacon did not stand alone. He is the representative of a 

 spirit that was active and widespread. It was creative ; and it formed 

 the scientific thought of succeeding centuries. Extracts from the 

 summary of Bridges follow : 



Opus Majus. — The four general causes of human ignorance — (1) subjection 

 to unworthy authority; (2) habit; (3) popular prejudice; (4) false conceit of 

 our own wisdom. Popular prejudice is a potent cause of error — pearls should not 

 be cast before swine. Aristotle, wisest of philosophers, was not perfect. Avicenna 

 sees where Aristotle erred; Averroes corrects Avicenna. Errors are found 

 among the fathers of the church. By the habit of discussing received opinion 

 we cease to be its slaves. The best Greek thought was not known to the Latin 

 fathers. The early church made no use of Greek science, and the same is true 

 of Bacon's own day, though without a good excuse. 



The Connection of Philosophy with Theology. — Eeason comes from 

 God, therefore philosophy is divine. It is not an invention of heathen 

 nations. The business of philosophy is to furnish a criterion of knowl- 

 edge. All speculative philosophy has moral philosophy for its end 

 and aim. 



* See a paper on Roger Bacon in The Popltlar Science Monthly, January, 

 1902. 



