In antiquity, the expertise of the Babylonians in matters of the heavens was legendary and the roots of both western astronomy and astrology are traceable in cuneiform tablets going back to the second and first millennia B.C. The Heavenly Writing discusses Babylonian celestial divination, horoscopy, and astronomy, their differentiations as well as interconnection and their place in Mesopotamian intellectual culture. Focusing chiefly on celestial divination and horoscopes, it traces the emergence of personal astrology from the tradition of celestial divination and the way astronomical methods were employed for horoscopes. It further takes up the historiographical and philosophical issue of the nature of these Mesopotamian 'celestial sciences' by examining elements traditionally of concern to the philosophy of science (empiricism, prediction, and theory) in relation to the Babylonian material without sacrificing the ancient methods, goals, and interests to a modern image of science. This book will be of particular interest for those concerned with the early history of science and the problems introduced by modern distinction between science, magic, and religion for the study and understanding of ancient cultures.