Aristotle

Academy  -   · Run by Plato, the Academy was the center of Greek learning. Aristotle spent twenty years there and owes a great deal of his life's work to this formative influence.

City-state  -   · A self-governing political unit that is sometimes under the power of an overseeing nation, as Athens was in Greece.

Four Causes -   · Aristotle's classification of the kinds of causes that a natural philosopher must investigate: 1) the constituent factor; 2) the form or pattern; 3) the immediate origin; and 4) the end or purpose.

Good life -   · For Aristotle, the good life required community participation, for man was incomplete otherwise. Since reason and language are what set man apart from the other animals, he must exercise them in a public forum to live a fulfilling life.

Lyceum -   · The rival school that Aristotle set up after he returned to Athens. While the Academy continued to thrive on mostly mathematical courses of study, Aristotle's school, the Lyceum, focused more on biology and natural history. It was here that Aristotle wrote most of his surviving works.

Substratum -   · A substance that underlies the real attributes of the material world.

Syllogism -   · A syllogism consists of certain assumptions or premises from which a conclusion can be deduced. The syllogism was the basic element on which Aristotle's logical system rested.

Teleology  -   ·  The consideration of natural ends or purposes in explaining phenomena.

Unmoved Mover -   · The first cause of all motion that is itself unmoved. Aristotle extended this natural science concept to his theology, arguing that the Unmoved Mover was equivalent to God. The being is perfect and eternal but does not take an interest in the world.

Alexander -  The Macedonian king who would conquer the Persian Empire. Aristotle served as his tutor for three years.

Callisthenes -  Nephew of Aristotle and official historian of the Persian expedition. Callisthenes died a martyr because he refused to submit to the King's policies.

Eudemus -  Friend of Aristotle's at the Academy. Eudemus's death inspired a work on the immortality of the soul.

Hermeias -  A close friend of Aristotle who became allied with Philip II in planning for the Persian conquest. Hermeias was captured and tortured, but he did not betray his alliance. Aristotle wrote a hymn upon his death.

Philip II -  Alexander's father and King of Macedonia. Philip II invited Aristotle to serve as his son's tutor.

Plato -  Aristotle spent twenty years at Plato's Academy. Nearly all of his work can, to some extent, be traced back to Plato's influence, though he also disagreed with much of Plato's thought.

Xenocrates -  Academy colleague who left with Aristotle upon Plato's death. Xenocrates would later assume leadership of the Academy, and Aristotle went on to form the Lyceum.