Latin Christendom.  For he who knows not mathematics cannot know any other sciences; and what is more, he cannot discover his own ignorance or find its proper remedies.”  Geography, chronology, arithmetic, music, are brought into something of scientific form, and like rapid sketches are given of the question of climate, hydrography, geography, and astrology.  The subject of optics, his own especial study, is treated with greater fulness; he enters into the question of the anatomy of the eye besides discussing problems which lie more strictly within the province of optical science.  In a word, the “Greater Work,” to borrow the phrase of Dr. Whewell, is “at once the Encyclopedia and the Novum Organum of the thirteenth century.”  The whole of the after-works of Roger Bacon—­and treatise after treatise has of late been disentombed from our libraries—­are but developements in detail of the magnificent conception he laid before Clement.  Such a work was its own great reward.

From the world around Roger Bacon could look for and found small recognition.  No word of acknowledgement seems to have reached its author from the Pope.  If we may credit a more recent story, his writings only gained him a prison from his order.  “Unheard, forgotten, buried,” the old man died as he had lived, and it has been reserved for later ages to roll away the obscurity that had gathered round his memory, and to place first in the great roll of modern science the name of Roger Bacon.

[Sidenote:  Scholasticism]

The failure of Bacon shows the overpowering strength of the drift towards the practical studies, and above all towards theology in its scholastic guise.  Aristotle, who had been so long held at bay as the most dangerous foe of mediaeval faith, was now turned by the adoption of his logical method in the discussion and definition of theological dogma into its unexpected ally.  It was this very method that led to “that unprofitable subtlety and curiosity” which Lord Bacon notes as the vice of the scholastic philosophy.  But “certain it is”—­to continue the same great thinker’s comment on the Friars—­“that if these schoolmen to their great thirst of truth and unwearied travel of wit had joined variety of reading and contemplation, they had proved excellent lights to the great advancement of all learning and knowledge.”  What, amidst all their errors, they undoubtedly did was to insist on the necessity of rigid demonstration and a more exact use of words, to introduce a clear and methodical treatment of all subjects into discussion, and above all to substitute an appeal to reason for unquestioning obedience to authority.  It was by this critical tendency, by the new clearness and precision which scholasticism gave to enquiry, that in spite of the trivial questions with which it often concerned itself it trained the human mind through the next two centuries to a temper which fitted it to profit by the great disclosure of knowledge that brought about