reached the summit of its influence and popularity. In the course of his argument Oresme gives an admirable account of the nature of hallucination and the parts it may play in perverting knowledge; not only so but he explains also the fallibility of the normal senses in respect of organic defects, of media, of false inference, of association, of imposition of the imagination, and so forth. Under such circumstances, he says, a mystic might conceive himself to have been visited by an angel! FOOTNOTES: [1] To bring the oration within the time allotted, this portion, and the paragraphs on astrology added as an appendix, were omitted. For the same reason the paragraphs on scepticism (p. 82) were also omitted but by inadvertence have held their continuity in the text. It is customary to print the text as delivered; and this must be my excuse for the cumbrous apparatus of notes, much of which might have been taken into an enlarged text. The notes are necessary to fortify statements which orally may pass, but do not satisfy a reader. [2] The “humoral doctrine” is imperfectly known. The four _elements_ are earth, water, air, fire; the four _qualities_ are hot, cold, moist, dry; the four _humours_ are blood, phlegm, yellow bile, black bile. By permutation of these were obtained the endless elaborations of the galenist doctrine which for many centuries blinded Europe not to the truth only, but also to the clinical and physiological methods, example, and attainments of Galen himself. [3] “Nec ullum satis validum imperium erat coercendis seditionibus populi, flagitia hominum ut cæremonias deum protegentis.” Tac. Ann. III. 60. [4] It must not be supposed that the idealism of Plato and the mysticism of the East were alike, or even akin. Plato was a Greek; his mind, as we appreciate such qualities, was sane and lucid: he had no yearning whatever for absorption in the Infinite; but rather, like Aristotle, for a noble life. [5] “Oftener on her knees than on her feet Died every day she lived.” Macbeth IV. 3. [6] I see in recent reports of Egyptian exploration that at Oxyrhynchus Plato was represented with curious persistence by the Phædo and the Laches; and these treatises appear in the early Fayyum papyri. [7] A few axioms, collected from the physical and metaphysical treatises (perhaps by Cassiodorus from Boetius), were current from an early date. The translations of Boetius must for a time have lain in some neglect?