Born in northern Greece (his father was a doctor who's patents included the king of Masadonia), at the age of 17 Aristotle went to Athens to study under Plato, and remained at the academy for nearly 20 years, until Plato's death in 348 or 347 BCE. Aristotle then left Athens for a while until he was invited to return to Masadonia by Philip to tutor Alexander (the Great). Aristotle founded his own philosophical school (remains of this school where found in 1996). He worked there until Alexander's death in 323 BCE when the Athenians, in a strongly anti Masadonian mood brought a formal charge of impiety against him (as with Socrates). Aristotle escaped to Chalcis but died there the following year aged 62. He married twice and had a son, Nicomachus by his second wife.
His philosophical interests covered an extremely wide area. He composed major studies of logic, ethics, and metaphysics, but also wrote on epistemology, physics, mathematics, biology, meteorology, dynamics, psychology, rhetoric, dialectics, aesthetics, and politics.
Aristotle's philosophical development is difficult to determine chronologically. Many of his works read like notebooks or possibly lecture notes. His writing reflect the activity of thinking itself uncluttered by rhetoric or stylistic affection. Let us look at just two of his interests, ethics and what he has to say about Plato's "Ideal Forms".
In his nichomachean ethics Aristotle sets out to give an account of the good life for humans. This is seen as intellectual contemplation and virtuous action stemming from a virtuous character. Virtuous action is what the person with practical wisdom would choose, and the practically wise are those who can deliberate successfully towards well being. He examines the characteristic roles of desire, goals, imagination, emotion, and intuition in the choices and intellectual action of the virtuous. Aristotle's own position is not always clear or consistent. Thus he remarks that the virtuous see what is good, but elsewhere writes that the good is so because it appears to be so to the virtuous.
Aristotle was convinced that teleological explanation was the key to proper study of natural organisms. What determined what counted as its successful operation: it achieving what is good for it to achieve. Thus the teleological goal of a man is to live a live of a given kind (e.g. or rational activity) and the rest of his nature is designed so as to achieve this intrinsic goal. The distinctive goal of each biological kind is what determines its respective essence. Examining Plato's theory of Ideal Forms Aristotle concluded that universals could not exist by themselves but only in particular things. Since substances must be capable of independent existence, it appears that they cannot be universals but must be particulars, however this generated a dilemma as Aristotle also believed that only universals are definable. Thus if substances are knowable they cannot be particulars. Needless to say this work has given rise to a huge amount of scholarly debate. Aristotle did not have a perfectly unified and inished theory. He was too cautious and scrupulous a thinker to carry through a program without constant refinement and attention to detail. He was constantly classifying and reclassifying objects in the animal world as well as in the world of abstractions.
He did not succeed in integrating his beliefs into a complete and unified theory. His writings seem to reflect the nature of intellectual contemplation itself.