But it was not only the new birth of sentiment and emotion which quickened these arts: it was also the aroused curiosity of men concerning themselves, their history, and the earth. They felt their own ignorance. The vast region of the unknown, which encircled with its immeasurable spaces the little tract of the known world, appealed to their fancy and their spirit of enterprise, with its boundless promise and its innumerable allurements to adventure. Learning, long confined and starved in the cell of the monk, was coming out into the open world, and was gathering fresh stores alike from the past and the present. The treasures of the wisdom and knowledge of the Greeks were eagerly sought, especially in translations of Aristotle,--translations which, though imperfect indeed, and disfigured by numberless misinterpretations and mistakes, nevertheless contained a body of instruction invaluable as a guide and stimulant to the awakened intelligence. Encyclopedic compends of knowledge put at the disposition of students all that was known or fancied in the various fields of science. The division between knowledge and belief was not sharply drawn, and the wonders of legend and of fable were accepted with as ready a faith as the actual facts of observation and of experience. Travelers for gain or for adventure, and missionaries for the sake of religion, were venturing to lands hitherto unvisited. The growth of knowledge, small as it was compared with later increase, widened thought and deepened life. The increase of thought strengthened the faculties of the mind. Man becomes more truly man in proportion to what he knows, and one of the most striking and characteristic features of this great century is the advance of man through increase of knowledge out of childishness towards maturity. The insoluble problems which had been discussed with astonishing acuteness by the schoolmen of the preceding generation were giving place to a philosophy of more immediate application to the conduct and discipline of life. The 'Summa Theologica' of St. Thomas Aquinas not only treated with incomparable logic the vexed questions of scholastic philosophy, but brought all the resources of a noble and well-trained intelligence and of a fine moral sense to the study and determination of the order and government of the universe, and of the nature and destiny of man.