Page:Science and medieval thought. The Harveian oration delivered before the Royal College of Physicians, October 18, 1900 (IA sciencemedievalt00allbrich).pdf/120

 portents in the skies. When we read the doctrines of Aristotle on the celestial beings, it is indeed somewhat strange that upon him, upon Plato, and upon the Ionians, the "judicia astrorum" had even less hold than the myth- ology: so truly poised, even in the infancy of science, were the cosmic speculations of this wonderful race. The Romans by their Etruscan tradition held to astro- logy, chiefly derived from Chaldea and Egypt, and by them it was mixed with grosser folk magic; yet even in Rome there were many to repudiate it, not only such Grecian spirits as Cicero but also such Romans as Juvenal; as in Harvey's time it was assailed by the irony of Pascal and of La Fontaine. Even in the twelfth century John of Salisbury had not failed to turn his light artillery upon astrology.

This art of forecast naturally attached itself closely to that of medicine; and in its decrepitude still it clung to medicine like a parasite. And as parasites in the field of pathology, so astrology brought with it other noxious superstitions and follies even worse than itself. In England it survived till the witty attack of Swift killed Partridge and astrology together; yet to this day many of its notions are embedded in our common speech.

Ptolemy among his good services did one ill to mankind by his Tetrabiblon or "Quadripertit," an astrological treatise which was current with the Almagest in the Western Schools. This authoritative treatise, together with the Aristotelian conception of the heavens, gave to astrology the aspect of a regular science with its own principles and methods; a science admired and