"The term 'Arabian Parts' is misleading. The medieval Arab astrologers inherited their art from a long-established tradition, which they did much to refine and develop, but did not originate. References to the parts are found in all the major astrological texts that have survived from Greek and Roman times. One such account is given in the Mathesis of Firmicus Maternus, written in the 4th century.

"Greek lots (also known as arabic parts) are sensitive points in a birth chart based upon the positions of the planets at birth, and the ascendant (with a few exceptions). The theory is that the planets in the heavens signify the more general circumstances that exist in the world at any given moment in time. What makes these planetary relationships unique to the individual is the way the individual exists in them, in relation to their ascending degree and sign.