Alexander’s tutor:

Nectanebus is said to have become Alexander’s tutor, using as text-book The Secret of Secrets, a book by Aristotle, later lost. This, among other things, circulated a knowledge of and respect for astrology. It did Nectanebus no good, however, for when the child was 12 years old he tipped the astrologer over a cliff to prove that he could not foretell the time of his own death. But at least it apparently provide tips for the future world general — such as that he should never take a laxative except when the Moon was in Scorpio, Libra or Pisces, and that severe constipation would result were he to be unwise enough to take one while the Moon was in Capricorn.