The dichotomy between 'practical' and 'theoretical' astronomy in ancient   and late antique literature
  In Plato's dialogues Republic and Laws, the most important disciplines for the best education of the rulers of the city are identified with arithmetic, geometry and astronomy. Those disciplines, however, are not intended for practical applications, but to reach the truth and see the form of good. In particular, another dialogue, Epinomis, stresses on the relevance of astronomy itself as main discipline, since it coincides with the study of the gods, that is, the planets and the heaven. According to Epinomis, the wise astronomer does not observe the risings and settings of stars for practical applications such as the farmer calendar, but he studies the orbits of the planets. Therefore, the 'practical' astronomy of farmers appears intrinsically less important than the 'theoretical' one, i.e. the study of the planetary motions. We discuss the possibly far-reaching negative implications of such a specific discrimination. We report some examples taken from Greek and Latin literature illustrating the difficulties of a coherent description of the risings and settings of stars that was attempted by scholars, and should have been of little help for farming. We conclude by pointing out the practical importance of astronomy (intended in a broad sense) even today, and of the dangers of the separation or discrimination of disciplines and sub-disciplines for the culture during the present global economic crisis. 
Elio Antonello
physics.hist-ph