Pythagoras, the famous Greek mathematician (570-495 BCE), believed numbers had mystical properties and contributed significantly to astrological calculations. His school studied the "music of the spheres" - the idea that planets create harmonious mathematical relationships.
The aspects used in astrology (conjunction at 0°, sextile at 60°, square at 90°, trine at 120°, opposition at 180°) are based on Pythagorean geometry and musical harmonics.
Pythagoras believed that understanding these numerical relationships could reveal cosmic truths about reality.