Aristotle (384 - 322 BC) is considered by many to have been the greatest thinker of all time and, alongside Plato, is certainly one of the most important philosophers of antiquity. His work covered a prodigious variety of subjects as diverse as abstract philosophy, politics, ethics, biology, astronomy, literary criticism and the forgotten art of rhetoric.

Born in Stagirus, a city of the Chalcidic peninsula on the north-west coast of the Aegean Sea, he was the son of Nicomachus - physician to Amyntas III and, subsequently, to Philip of Macedon, who was father of Alexander the Great. Aristotle belonged by birth to a guild called the Asclepiadae in which the medical profession was hereditary. Aged 17, he enrolled as a scholar at the Academy in Athens, the school of another great philosopher of that era, Plato. Referred to by his mentor as the 'mind of the school', Aristotle remained there for 20 years, leaving only on the death of Plato in 347 BC. He was reputedly upset at being passed over as new head of the Academy in deference to Speusippus, but would go on to exceed Plato in terms of breadth of knowledge and understanding of the world at large.

Aristotle found temporary occupation in Asia Minor with his friend and fellow Platonic scholar, Hermeias, whose sister, Pythias he married. This was shortly before he was personally invited by the Macedonian court to be the tutor of future King and Emperor Alexander. Thus he was a key witness to the period of dominance of Macedonia over the Hellenic peninsula and, latterly, the campaigns in which Alexander led his Empire to victory over the Persians. When Alexander, then aged 20, ascended the throne, he presented Aristotle with a large sum of money to establish his own school in Athens, despite the Stagirite's vocal detestation of monarchy and its accessories.

The Lyceum was to provide the home of Aristotle's 'Peripatetic School' (derived from the Greek 'to walk about', because of the manner of Aristotle's teachings) for the remaining years of his life and indeed for a long period afterwards. He collected an enormous library of books and founded his very own museum. He led his pupils in every existing area of knowledge and research, laying the foundations for much of modern day science. Rather than the mathematics that had predominated in the Platonic Academy, the Peripatetic School was more deeply concerned with historical and biological theorising.

Following the death of Alexander and the ensuing outbreak of anti-Macedonian sentiment in Athens in 323 BC, Aristotle was charged with impiety and fled the city-state, fearing the same ignominious end as Socrates. He settled in Chalcis - mother city of his native Stagirus - on the island of Euboea, where he died the following year at the age of 62. He left a second wife, Herpyllis, a son, Nicomachus, and a daughter.

Aristotle is believed to have produced a vast number of written works, though relatively little of his material remains available to us today. His most important works include Politics, Metaphysics, Ethics, De Anima and Poetics.