Everything we read by Aristotle was never meant for the public
Aristotle wrote polished dialogues for a general audience, and almost all of them are lost. What survives, about a third of his output, is essentially teaching material for students at his school, probably edited by later hands. Those lecture notes still shaped logic, science and theology for roughly two thousand years.
Born in 384 BC at Stagira, about 55 kilometres east of modern Thessaloniki, Aristotle was the son of Nicomachus, physician to King Amyntas of Macedon, which may explain his early pull toward biology. Orphaned young, he was raised by a guardian, Proxenus of Atarneus. At seventeen or eighteen he entered Plato's Academy in Athens, where Plato reportedly called him the mind of the school, and he stayed almost twenty years.
After Plato's death he left Athens, perhaps unhappy with the new head Speusippus, perhaps because of anti-Macedonian feeling. At Assos in Asia Minor and then on Lesbos, he and Theophrastus studied plants and sea creatures. In 343 or 342 BC Philip II hired him to tutor the thirteen-year-old Alexander at Mieza near Pella. He gave the prince an annotated Iliad and urged conquest in the east with a starkly ethnocentric view of Persians, though teacher and pupil later fell out over how to rule cities and treat the conquered.
Back in Athens, as a resident foreigner barred from owning property, he rented the Lyceum; its covered walkway, the peripatos, gave his Peripatetic school its name. Over twelve years he and students such as Theophrastus built a library of manuscripts, maps and specimens, and he produced the works now known as Physics, Metaphysics, Nicomachean Ethics, Politics and Poetics. His Prior Analytics is the earliest systematic study of logic, dominant in the West until nineteenth-century mathematical logic; Kant even thought logic had been completed with him.
When Alexander died, Athens turned hostile again. Accused of impiety in 322 BC, Aristotle fled to Chalcis, reportedly saying he would not let the Athenians sin twice against philosophy, a pointed nod to Socrates. He died there that year. His papers passed to Theophrastus and then lay hidden in Asia Minor until a collector bought them. Medieval Muslim scholars called him the First Teacher, and to Thomas Aquinas he was simply the Philosopher; his physics held sway until classical mechanics, and his ethics has revived with modern virtue ethics.
Source: Aristotle
