Transcript: Aristotle, who lived in the fourth century BC, was the most influential and famous Greek philosopher.  He founded a second University, the Lyceum, near Athens. He was a pupil of Plato.  He wrote and lectured on many subjects, including marine biology, botany, anatomy, economics, politics and meteorology.  He developed the tools of logic that are the basis of the scientific method.  He had his own observatory, and he made observations of stars and planets.  In cosmology he developed a system that would stay in place as the current theory for 2000 years.  Even though it was wrong, in Aristotle's cosmology the Earth was round, but it was stationary at the center of a universe where the stars formed the outermost sphere.  This is called the geocentric cosmology.