Aristotle had a profound impact, through his writings, on the medieval and Islamic philosophies, and he was one the most important influences on the scientific and intellectual traditions of the western world. He wrote about virtually all aspects of thought, including philosophy, politics, physics, logic, biology and cosmology. Born in Stagirus, a port of Macedonia, his father died while Aristotle was quite young and he was placed in the care of a family friend who sent him to Athens in 367 BC. It was here that he studied at Plato's academy, eventually succeeding Plato after his death around 348 BC. Around this time a wave of anti-Macedonian feeling in Athens forced Aristotle to leave for twelve months, taking up a tour of Asia Minor where he studied natural history. After returning to Athens he began his own school called the Lyceum (so-called because of its proximity to the temple of Apollo Lyceius). It was here that his followers became known as 'peripatetics', supposedly because Aristotle would pace up and down while he was lecturing.
A major Aristotelian theme was the theory that the Earth was the centre of an eternal universe. He taught that everything below the orbit of the Moon was composed of the four elements: Earth, Fire, Air and Water, and that these were all subject to generation, destruction, qualitative change and rectilinear motion.
Aristotle correctly observed that the Earth was spherical by noticing its shadow cast upon the Moon during a lunar eclipse and that the stars changed position as one travelled further South or North. As a result of these observations, Aristotle calculated the Earth's diameter, overestimating by 50%, a remarkably accurate result considering the apparatus he was using. He was a prolific thinker and extremely influential, and his work was accepted almost religiously until the sixteenth and seventeenth centuries.
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