Eudosso di Cnido

Eudoxus of Cnidus is one of the most eminent figures of his time (V-IV century. BC). The sources describe his various interests, ranging from geometry to astronomy, from geography to medicine, from ethics to legislation: with his studies, he takes a decisive contribution to the development of specialized languages and to the origin of scientific literature. The proportions' theory in Euclid's 'Elements' V as well as the method of exhaustion in XII, are both due to Eudoxus; he also studies the golden section and the duplication of the cube. In astronomy, tradition suggests that he's the first to investigate the difficult problem of planetary motion, providing as solution a complex system of homocentric spheres. He also gives the first systematic description of the celestial sphere and he sets a luni-solar cycle of eight years, used for the preparation of a 'parapegma' (astro-meteorological calendar). The relationship with Plato and the Academy is controversial: certainly, he supportes original positions in the debate on ideas and pleasure.