Astrology is a disease, not a science. All sorts of superstitions thrive under its shadow. Only fools and charlatans lend value to it.
Variant translation: Astrology is a sickness, not a science...It is a tree under the shade of which all sorts of superstitions thrive.
Mishneh Torah: Maimonides' Code of Law and Ethics (Hebrew Publishing Company, 1974), p. 35