Born: 384 BC in Stagirus, Macedonia, Greece
Died: 322 BC in Chalcis, Euboea, Greece
Aristotle was not primarily a mathematician but made important contributions by systematising deductive logic. He wrote on physical subjects: some parts of his Analytica posteriora show an unusual grasp of the mathematical method. Primarily, however, he is important in the development of all knowledge for, as the authors of write:-
Aristotle, more than any other thinker, determined the orientation and the content of Western intellectual history. He was the author of a philosophical and scientific system that through the centuries became the support and vehicle for both medieval Christian and Islamic scholastic thought: until the end of the 17th century, Western culture was Aristotelian. And, even after the intellectual revolutions of centuries to follow, Aristotelian concepts and ideas remained embedded in Western thinking.
Aristotle was born in Stagirus, or Stagira, or Stageirus, on the Chalcidic peninsula of northern Greece. His father was Nicomachus, a medical doctor, while his mother was named Phaestis. Nicomachus was certainly living in Chalcidice when Aristotle was born and he had probably been born in that region. Aristotle's mother, Phaestis, came from Chalcis in Euboea and her family owned property there.
There is little doubt that Nicomachus would have intended Aristotle to become a doctor, for the tradition was that medical skills were kept secret and handed down from father to son. It was not a society where people visited a doctor but rather it was the doctors who travelled round the country tending to the sick. Although we know nothing of Aristotle's early years it is highly likely that he would have accompanied his father in his travels. We do know that Nicomachus found the conditions in Chalcidice less satisfactory than in the neighbouring state of Macedonia and he began to work there with so much success that he was soon appointed as the personal physician to Amyntas III, king of Macedonia.
There is no record to indicate whether Aristotle lived with his father in Pella, the capital of Macedonia, while Nicomachus attended to king Amyntas at the court there. However, Aristotle was certainly friendly with Philip, king Amyntas's son, some years later and it seems reasonable to assume that the two, who were almost exactly the same age, had become friendly in Pella as young children.
When Aristotle was about ten years old his father died. This certainly meant that Aristotle could not now follow in his father's profession of doctor and, since his mother seems also to have died young, Aristotle was brought up by a guardian, Proxenus of Atarneus, who was his uncle (or possibly a family friend as is suggested by some authors). Proxenus taught Aristotle Greek, rhetoric, and poetry which complemented the biological teachings that Nicomachus had given Aristotle as part of training his son in medicine. Since in latter life Aristotle wrote fine Greek prose, this too must have been part of his early education.
In 367 BC Aristotle, at the age of seventeen, became a student at Plato's Academy in Athens. At the time that Aristotle joined the Academy it had been operating for twenty years. Plato was not in Athens, but rather he was on his first visit to Syracuse. We should not think of Plato's Academy as a non-political organisation only interested in abstract ideas. The Academy was highly involved in the politics of the time, in fact Plato's visit to Sicily was for political reasons, and the politics of the Academy and of the whole region would play a major role in influencing the course of Aristotle's life.
When Aristotle arrived in Athens, the Academy was being run by Eudoxus of Cnidos in Plato's absence. Speusippus, Plato's nephew, was also teaching at the Academy as was Xenocrates of Chalcedon. After being a student, Aristotle soon became a teacher at the Academy and he was to remain there for twenty years. We know little regarding what Aristotle taught at the Academy. In  Diogenes Laertius, writing in the second century AD, says that Aristotle taught rhetoric and dialectic. Certainly Aristotle wrote on rhetoric at this time, issuing Gryllus which attacked the views on rhetoric of Isocrates, who ran another major educational establishment in Athens. All Aristotle's writings of this time strongly support Plato's views and those of the Academy.
Towards the end of Aristotle's twenty years at the Academy his position became difficult due to the political events of the time. Amyntas, the king of Macedonia, died around 369 BC, a couple of years before Aristotle went to Athens to join the Academy. Two of Amyntas's sons, Alexander II and Perdiccas III, each reigned Macedonia for a time but the kingdom suffered from both internal disputes and external wars. In 359 BC Amyntas's third son, Philip II came to the throne when Perdiccas was killed fighting off an Illyrian invasion. Philip used skilful tactics, both military and political, to allow Macedonia a period of internal peace in which they expanded by victories over the surrounding areas.
Philip captured Olynthus and annexed Chalcidice in 348 BC. Stagirus, the town of Aristotle's birth, held out for a while but was also defeated by Philip. Athens worried about the powerful threatening forces of Macedonia, and yet Aristotle had been brought up at the Court of Macedonia and had probably retained his friendship with Philip. The actual order of events is now a little uncertain. Plato died in 347 BC and Speusippus assumed the leadership of the Academy. Aristotle was certainly opposed to the views of Speusippus and he may have left the Academy following Plato's death for academic reasons or because he failed to be named head of the Academy himself. Some sources, however, suggest that he may have left for political reasons before Plato died because of his unpopularity due to his Macedonian links.
Aristotle travelled from Athens to Assos which faces the island of Lesbos. He was not alone in leaving the Academy for Xenocrates of Chalcedon left with him. In Assos Aristotle was received by the ruler Hermias of Atarneus with much acclaim. It is likely that Aristotle was acting as an ambassador for Philip and he certainly was treated as such by Hermias. Aristotle married Pythias, the niece and adopted daughter of Hermias, and they had one child, a daughter also called Pythias. However, Aristotle's wife died about 10 years after their marriage. It is thought that she was much younger than Atistotle, being probably of age of about 18 when they married.
On Assos, Aristotle became the leader of the group of philosophers which Hermias had gathered there. It is possible that Xenocrates was also a member of the group for a time. Aristotle had a strong interest in anatomy and the structure of living things in general, an interest which his father had fostered in him in his early years, that helped him to develop a remarkable talent for observation. Aristotle and the members of his group began to collect observations while in Assos, in particular in zoology and biology. Barnes writes in that Aristotle's:-
... studies on animals laid the foundations of the biological sciences; and they were not superseded until more than two thousand years after his death. The enquiries upon which those great works were based were probably carried out largely in Assos and Lesbos.
Aristotle probably begun his work Politics on Assos as well as On Kingship which is now lost. He began to develop a philosophy distinct from that of Plato who had said the kings should be philosophers and philosophers kings. In On Kingship Aristotle wrote that it is:-
... not merely unnecessary for a king to be a philosopher, but even a disadvantage. Rather a king should take the advice of true philosophers. Then he would fill his reign with good deeds, not with good words.
However, Aristotle's time in Assos was ended by political events. The Persians attacked the town and Hermias was captured and executed. Aristotle escaped and stopped on the island of Lesbos on his way to Macedonia. It was more than a passing visit for he remained there for about a year and must have had the group of scientists from Assos with him for they continued their biological researches there.
Macedonia was now at peace with Athens, for Philip had made a treaty in 346 BC. In 343 BC Aristotle reached the Court of Macedonia and he was to remain there for seven years. The often quoted story that he became tutor to the young Alexander the Great, the son of Philip, is almost certainly a later invention as was pointed out by Jaeger, see . Grayeff in suggests that Philip saw in Aristotle a future head of the Academy in Athens. Certainly this would have suited Philip well for Speusippus, the then head of the Academy, was strongly opposed to Philip and strongly encouraging Athens to oppose the rise of Macedonia.
The treaty between Athens and Macedonia began to fall apart in 340 BC and preparations for war began. The following year Speusippus died but Aristotle, although proposed as head of the Academy, was not elected. The position went to Xenocrates and Philip lost interest in his support for Aristotle. He moved back to his home in Stagirus and took with him to Stagirus his circle of philosophers and scientists.
Aristotle did not marry again after the death of his wife but he did form a relationship with Herpyllis, who came from his home town of Stagirus. It is not clear when they first met but together they had a son, Nicomachus, named after Aristotle's father.
Philip was now at the height of his power but, as so often happens, that proved the time for internal disputes. Aris