in diagrams and maps which interpret with the greatest possible distinctness Plato's conception of the nether world, and of the destiny of departed souls. In the light of this topography, the writer subjects the Greek text to criticism and revises Aristotle's Meteorology, II, 2 (in order to harmonize it with the Platonic account of the Phædo) by striking out οἱον εἰ ῥεῖν ῆρξαντο κάτωθεν, ἄνωθεν εἰσβάλλειν, which Baensch regards as an early gloss. W. A. H.
No attempt is made in this article to put into systematic form the disconnected paragraphs of the "Meditations," but a clear enumeration of the chief ethical ideas is given—ideas which, as Lindsay says, "made the Emperor the important connecting link between pagan and Christian thought." W. A. H.
Pfeffer points out that the most important information regarding the development of the Cartesian philosophy is found in the Discours and the Letters. The main series of the latter begin with the year 1629. In the spring of 1629 Descartes retired to Holland, carrying out a resolution he had formed towards the end of 1628 to leave Paris and find solitude for the working out of his "new philosophy." On April 16, 1629, he was registered at the little University of Franeker in North Holland. At this time his correspondence shows that he was engaged on the metaphysics, for on April 15, 1630, he wrote Mersenne: "Les 9 premiers mois que j'ai été en ce pays je n'ai travaille à autre chose (sc. qu'à la métaphysique)." Further, on November 25, 1630, he wrote Mersenne: "I do not say that I shall not some day complete a petit traité de métaphysique [published under the title: Meditationes] which I began when I was in Franeker."
Further, about the end of July he became interested through Reneri in the observations of the Jesuit Scheiner on the Parhelia, which drew him away from his metaphysical studies, and in October and November of 1629 he was in active correspondence with the optician Ferrier, of Paris, on the questions of dioptrics and mechanics. By the end of 1629 he had already formed the plan of his work on physics, which he hoped to complete in three years, as he announced in April of 1630, and by November, 1630, he had chosen the title Le monde. In January, 1632, he sent the first part of his Dioptrics to Golius, Professor of mathematics at Leyden. News of the condemnation of Galilei (July 22, 1633) reached Descartes in November, 1633, at a time when he was in a mood of indecision about his work Le monde, and about the end of the year he determined not to publish it. His motto became:"Bene vixit, bene qui latuit." In the summer of 635, he announced to Mersenne that he had separated the Dioptrics from
