How the study of physical phenomena in ancient Mesopotamia relates to the history of science is a question as important for the study of ancient Mesopotamia as it is for the history of science. It addresses both the nature of knowledge in the oldest literate culture as well as the historical reach of what we call science. If the essence of science is to be found in its systematization of knowledge about phenomena and in the various practices associated with such knowledge systemspractices such as celestial observation, prediction, and explanationthen science was a central part of cuneiform intellectual culture.Divination, magic, and medicine were integral parts of what the scribes termed "scholarship" (t ˙upsarrūtu, literally "the art of the scribe") as well as "wisdom" (nēmequ). Scholarship and wisdom were classified as a "secret of the great gods" (pirišti ilāni rabûti), referring to a conception of the origins of knowledge with the divine. Cuneiform knowledge was thus reserved for initiates, and injunctions against scribes who were not among the privileged few with access to texts classified as "secret" (pirištu) or "guarded" (nis ˙irtu) are known from the Middle Babylonian (ca. sixteenth to eleventh centuries bce) to the Late Babylonian (ca. fourth to first centuries bce) periods. 2 The classification of knowledge as secret applied to divinatory texts, incantations, apotropaic rituals against ominous signs, medical texts, scholarly commentaries on divinatory texts, and astronomical texts, and by the late first millennium the interrelations among these forms of knowledge become more apparent. A Late Babylonian astronomical text giving rules for calculating month lengths and intervals of lunar visibility around the full moon, 1 There are various abbreviations that are standard within Assyriology. Those unfamiliar with these may consult http://cdli.ox.ac.uk/wiki/abbreviations_for_assyriology.