The core beliefs of astrology were prevalent in most of the ancient world and are epitomized in the Hermetic maxim "as above, so below".
Tycho Brahe used a similar phrase to justify his studies in astrology: suspiciendo despicio, "by looking up I see downward".
Although the principle that events in the heavens are mirrored by those on Earth was once generally held in most traditions of astrology around the world, in the West there has historically been a debate among astrologers over the nature of the mechanism behind astrology.
The debate also covers whether or not celestial bodies are only signs or portents of events, or if they are actual causes of events through some sort of force or mechanism.
Although the connection between celestial mechanics and terrestrial dynamics was explored first by Isaac Newton with his development of a universal theory of gravitation, claims that the gravitational effects of the celestial bodies are what accounts for astrological generalizations are not substantiated by scientific research, nor are they advocated by most astrologers