Aristotle

Aristotle was born in Stagira, located in northern Greece, in 384 B.C. He died in Chalcis, on the Aegean island of Euboea, in 322 B.C. Aristotle's father had been court physician to the Macedonian king Amyntas II. Aristotle lost both of his parents when he was child, and was brought up by a friend of the family.

Aristotle wrote 170 books, 47 of which still exist more than two thousand years later. Aristotle was also a philosopher who wrote about ethics, psychology, economics, theology, politics, and rhetoric. Later inventions like the telescope and microscope would prove many of Aristotle's theories to be incorrect, but his ideas formed the basis of modern science.

Aristotle's most successful scientific writings were those on biology. He studied over five hundred animal species and dissected nearly fifty of them. He was particularly interested in sea life and observed that the dolphin brought forth its young alive and nourished the fetus by means of a special organ called a placenta. No fish did this, but all mammals did, so Aristotle classed the dolphin with the beasts of the field rather than with the fish of the sea. His successors did not follow his lead, and it took two thousand years for biologists to catch up to Aristotle in this respect.

In physics Aristotle was far less successful than in biology. He accepted the heavenly spheres of Eudoxus and Callippus and even added further to them, reaching a total of 54. He seemed to think of the spheres as having an actual physical existence. These lines to us are known as lines of latitude and lines of longitude.

Apparently, Aristotle was not an experimentalist for all that he was a close observer. He observed that rocks fell more quickly than feathers, but he made no attempt to arrange an observation of the falling of rocks of graded weight.

Aristotle's system of philosophy was never as influential in ancient times as Plato's. Aristotle's works may not have been published for some centuries after his death. After the fall of Rome, his work was lost to Europe, while Plato's works were, for the most part, retained. However, Aristotle's books survived among the Arabs, who valued them highly. Christian Europe regained Aristotle from the Arabs, translating his books into Latin in the twelfth and thirteenth centuries. From that time Aristotle replaced Plato as the Philosopher.

Most people in Aristotle's time