Page:The place of magic in the intellectual history of Europe.djvu/89

81] forth in the little volume known as the Tetrabiblos, or Quadripartitum. It would seem as if we ought to be able to regard a book by that noted geographer and astronomer as an example of the best science of his time, the middle of the second century. His works quickly became classics, and in the third century Porphyry commented on the Tetrabiblos. The Arabs eagerly accepted his writings, and it is generally held that in the Middle Ages his word was law in all the subjects of which he treated. The Tetrabiblos, therefore, would seem a landmark in the entire history of astrology as well as a crucial instance of how that branch of magic formed a part of science in the Roman Empire. True, Ptolemy does not cover the whole field of sidereal influence. He limits himself to the effects of the stars on man and does not attempt to trace out how they affect all varieties of matter and of life upon our globe. However, to make the stars control each individual man is the climax of astrology and implies that the heavenly bodies govern everything else here on earth. So the Tetrabiblos is a very satisfactory instance of belief in astrology by a scientist and its contents may well be briefly considered.

The first of the four books opens with the trite contention that the art itself is not to be rejected because