Abstract

In summary we have as follows, leaving aside here the complex and important cometary theories of the pre-socratics, Aristotle, and the Stoics. First, ca. 145-35 B.C.E. Nechepso-Petosiris wrote a book of astrology including a passage on cometary prognosis based on heavenly region of appearance. He assumed that comets were fiery without further ado. His view of comets seems to be that they appear in, move toward, or pause in, any quadrant of the sky. Their descriptions are irrelevant to their nature, serving only to identify them. Within the next century five further books were written. Epigenes refined the standard theory with details about whirl-winds and the like, referred to the Chaldaians, was also an astrologer, and has the simplest view of the planets 82). Although fundamentally Epigenes' theory is simple, it seems to have involved a detailed reworking of Aristotle's theory 83), perhaps making use of Hipparchos or of Hipparchos' Babylonian sources. First, the three outer planets by their conjunctions generate thunder and lightning. Then the events called trabes and faces are formed from.