41 



upon the originals but upon Arabic versions. It is also an appeal 

 for the cultivation of mathematics and for the freer use of obser- 

 vation and experiment. Lastly, it is an exposition, in clear and 

 vivid, if not always classical, Latin, of certain leading branches 

 of Science which Bacon had studied himself. Whewell has 

 spoken of the work as at once the Encyclopaedia and the Novum 

 Organon of the 13th Century. It makes no pretensions to the 

 teaching of any systematic doctrine as to the philosophy or logic 

 of Induction, nor did Roger Bacon attempt the sort of reform- 

 ation which at the time of Galileo had developed into organized 

 revolt against the teaching of Aristotle, and the authority of the 

 Church as touching matters of Science. Nor does the work 

 contain record of original discoveries. Ptolemy and the Arabian 

 Alhazen were the sources of the greater part at least of Bacon's 

 physical and astronomical learning. 



It is not likely thnt he invented gunpowder, for it seems to 

 have been known before his day. The use of magnifying glasses, 

 too, was known before his time, and the claim made for him by 

 Draper in his "History of the Intellectual Development of Europe" 

 that he described the true theory of the telescope is extravagant, 

 and seems to be b.ased on a very vague statement in one of Roger 

 Bacon's works to the effect that by means of optical contrivances 

 distant things could be made to look as if they were near, and 

 things low down may be made to appear high up, and so on. 



The fiist part of his yreat work deals with the four chief causes 

 of human ignorance. These are : ( i) The influence of weak and 

 unworthy authority. (2) The influence of custom. (3) The 

 influence of the opinion of the ignorant multitude. (4) The 

 desire to conceal ignorance under an ostentatious display of 

 learning. 



These four causes of human ignorance he describes as being 

 stumbling blocks in the way of wisdom, and as being the source 

 of all the ills which befall the human race. 



The second division of the Opus Majus is devoted to proving 

 that Theology is the one Science which is the mistress of all 

 others, and that all learning originally was conveyed in the form 

 of supernatural wisdom to the descendants of Noah. There is 

 one perfect wisdom, which is contained in the sacred Scriptures. 



The third division of the work discusses the utiHty of 

 grammar. It is a vij^orous defence of the value of knowledge of 

 languages. The late Professor Max MuUer gives this treatise the 

 credit of being in its way a sort of attempt at an introduction to 

 the Science of Philology. 



The fourth part of the book is the one upon which the 

 author chiefly prided himself. It is an exposition of what Roger 

 Bacon calls Mathematics, and under this term is included what 

 was then known of Geometry, .\stronomy. Mechanics, and 

 Geometrical Optics. It is in this work that we find the celebrated 



