The Mathematical Sciences (Quadrivium)
Four sister sciences—number, figure, harmony, and the turning heavens—form a single ladder lifting the soul from the visible toward the real.
The Greeks grouped the exact sciences into a famous quartet: arithmetic (number), geometry (figure and magnitude), harmonics (the ratios of musical sound), and astronomy (the ordered motion of the heavens). Plato, in Book VII of the Republic, prescribed this curriculum as the indispensable training that turns the mind away from the senses and prepares it for dialectic and the contemplation of intelligible reality. The Pythagoreans, especially Archytas, had already seen these fields as kindred and akin; later writers like Nicomachus systematized them, and the scheme passed into the medieval West as the "quadrivium," the fourfold path to wisdom.
Key passages(14)
De animae procreatione in Timaeo · Plutarch
De animae procreatione in Timaeo · Plutarch
De animae procreatione in Timaeo · Plutarch
Non Posse Suaviter Vivi Secundum Epicurum · Plutarch
Vitae philosophorum · Diogenes Laertius