Geronimo Cardano

(Girolamo Cardano; Hieronymus Cardanus). Born Sept. 24, 1501 (1506 by other accounts), in Pavia; died Sept. 21, 1576, in Rome. Italian philosopher, physician, and mathematician.

Cardano elaborated a cosmological system in De subtilitate rerum (1550) and De rerum varietate (1557) that was close to other formulations by the Renaissance natural philosophers (B. Telesio, G. Bruno). Although materialist features are noticeable—eternal matter is assumed to be the fundamental substance —a mystical Neoplatonism predominates. According to Cardano, the world is constructed out of three elements, earth, water, and air; matter has two properties, warmth and humidity. Fire is only a form of existence of the all-pervading and omnipresent celestial warmth, that is, of matter, which thus resembles the light of the Neoplatonists. The becoming of a thing is due to the world soul. The mind, identical in all men, is passive, and only a divine principle, which is placed in it, makes possible the knowledge of god in mystical exaltation. Cardano makes a distinction between the mind and the intellect, the active element of human consciousness; man understands the essence of things only where the object, as in mathematics, which is highest form of knowledge, is formed by the intellect and is assimilated to it.

Cardano’s natural philosophy is both the foundation and the final synthesis of his most diverse scholarly activity in astrology and alchemy, medicine and physics, mathematics, engineering, and psychology. His works played an important role in the development of algebra; he was one of the first in Europe to admit negative roots of equations. His name is linked with the formula for the solution of the reduced cubic equation (Cardano’s formula). Cardano also studied the transmission of motion and the theory of levers.