Babylonian Astrology - Limits of Early Knowledge - Astronomical Expertise

Astronomical Expertise

The second limitation was that the astronomical knowledge presupposed and accompanying early Babylonian astrology was, though essentially of an empirical character, limited and flawed. The theory of the ecliptic as representing the course of the Sun through the year, divided among twelve constellations with a measurement of 30° to each division, is of Babylonian origin, as has now been definitely proved; but it does not appear to have been perfected until after the fall of the Babylonian empire in 539 B.C.

Similarly, the other accomplishments of Babylonian astronomers, such as their system or rather systems of moon calculations and the drawing up of planetary tablets, belong to this late period, so that the golden age of Babylonian astronomy belongs not to the remote past, as was until recently supposed, but to the Seleucid period; i.e. after the advent of the Greeks in the Euphrates Valley.

From certain expressions used in astrological texts that are earlier than the 7th century B.C. it would appear, indeed, that the beginnings at least of the calculation of sun and moon eclipses belong to the earlier period, but here, too, the chief work accomplished was after 400 BC, and the defectiveness of early Babylonian astronomy may be gathered from the fact that as late as the 6th century BC an error of almost an entire month was made by the Babylonian astronomers in the attempt to determine through calculation the beginning of a certain year.

In a general way, the reign of law and order in the movements of the heavenly bodies was recognized, and indeed must have exercised an influence at an early period in leading to the rise of a methodical divination that was certainly of a much higher order than the examination of an animal's liver.

However, the importance that was laid upon the endless variations in the form of the phenomena and the equally numerous apparent deviations from what were regarded as normal conditions, prevented for a long time the rise of any serious study of astronomy beyond what was needed for the purely practical purposes that the priests as "inspectors" of the heavens (as they were also the "inspectors" of the sacrificial livers) had in mind.