ROGER BACON, it may be said, was many centuries in advance of his time; but it is equally true that he was the child of his time; this may account for his defects judged by modern standards. He owed not a little to his contemporaries: for his knowledge and high estimate of philosophy he was largely indebted to his Oxford master GROSSETESTE (_c_. 1175-1253), whilst PETER PEREGRINUS, his friend at Paris, fostered his love of experiment, and the Arab mathematicians, whose works he knew, inclined his mind to mathematical studies. He was violently opposed to the scholastic views current in Paris at his time, and attacked great thinkers like THOMAS AQUINAS (_c_. 1225-1274) and ALBERTUS MAGNUS (1193-1280), as well as obscurantists, such as ALEXANDER of HALES (_ob_. 1245). But he himself was a scholastic philosopher, though of no servile type, taking part in scholastic arguments. If he declared that he would have all the works of ARISTOTLE burned, it was not because he hated the Peripatetic's philosophy--though he could criticise as well as appreciate at times,--but because of the rottenness of the translations that were then used. It seems commonplace now, but it was a truly wonderful thing then: ROGER BACON believed in accuracy, and was by no means destitute of literary ethics. He believed in correct translation, correct quotation, and the acknowledgment of the sources of one's quotations--unheard-of things, almost, in those days. But even he was not free from all the vices of his age: in spite of his insistence upon experimental verification of the conclusions of deductive reasoning, in one place, at least, he adopts a view concerning lenses from another writer, of which the simplest attempt at such verification would have revealed the falsity. For such lapses, however, we can make allowances.