Aristotle provided a complex synthesis of the various philosophies existing prior to him
Aristotle's views profoundly shaped medieval scholarship
Some of Aristotle's zoological observations found in his biology, such as on the hectocotyl (reproductive) arm of the octopus, were disbelieved until the 19th century
He influenced Judeo-Islamic philosophies during the Middle Ages, as well as Christian theology, especially the Neoplatonism of the Early Church and the scholastic tradition of the Catholic Church
His works contain the earliest known formal study of logic, and were studied by medieval scholars such as Peter Abelard and Jean Buridan
Aristotle's influence on logic continued well into the 19th century
In addition, his ethics, though always influential, gained renewed interest with the modern advent of virtue ethics
Life 
In general, the details of Aristotle's life are not well-established
The biographies written in ancient times are often speculative and historians only agree on a few salient points
Aristotle was born in 384 BC in Stagira, Chalcidice, about 55 km (34 miles) east of modern-day Thessaloniki
His father, Nicomachus, was the personal physician to King Amyntas of Macedon
While he was young, Aristotle learned about biology and medical information, which was taught by his father
Both of Aristotle's parents died when he was about thirteen, and Proxenus of Atarneus became his guardian
Although little information about Aristotle's childhood has survived, he probably spent some time within the Macedonian palace, making his first connections with the Macedonian monarchy
At the age of seventeen or eighteen, Aristotle moved to Athens to continue his education at Plato's Academy
He probably experienced the Eleusinian Mysteries as he wrote when describing the sights one viewed at the Eleusinian Mysteries, "to experience is to learn" [παθείν μαθεĩν]
Aristotle remained in Athens for nearly twenty years before leaving in 348/47 BC
Aristotle then accompanied Xenocrates to the court of his friend Hermias of Atarneus in Asia Minor
After the death of Hermias, Aristotle travelled with his pupil Theophrastus to the island of Lesbos, where together they researched the botany and zoology of the island and its sheltered lagoon
While in Lesbos, Aristotle married Pythias, either Hermias's adoptive daughter or niece
They had a daughter, whom they also named Pythias
In 343 BC, Aristotle was invited by Philip II of Macedon to become the tutor to his son Alexander
Aristotle was appointed as the head of the royal Academy of Macedon
During Aristotle's time in the Macedonian court, he gave lessons not only to Alexander but also to two other future kings: Ptolemy and Cassander
Aristotle encouraged Alexander toward eastern conquest, and Aristotle's own attitude towards Persia was unabashedly ethnocentric
By 335 BC, Aristotle had returned to Athens, establishing his own school there known as the Lyceum
Aristotle conducted courses at the school for the next twelve years
While in Athens, his wife Pythias died and Aristotle became involved with Herpyllis of Stagira
They had a son whom Aristotle named after his father, Nicomachus
If the Suda  an uncritical compilation from the Middle Ages  is accurate, he may also have had an erômenos, Palaephatus of Abydus
This period in Athens, between 335 and 323 BC, is when Aristotle is believed to have composed many of his works
He wrote many dialogues, of which only fragments have survived
Those works that have survived are in treatise form and were not, for the most part, intended for widespread publication; they are generally thought to be lecture aids for his students
His most important treatises include Physics, Metaphysics, Nicomachean Ethics, Politics, On the Soul and Poetics
A widespread tradition in antiquity suspected Aristotle of playing a role in Alexander's death, but the only evidence of this is an unlikely claim made some six years after the death
Following Alexander's death, anti-Macedonian sentiment in Athens was rekindled
He died in Chalcis, Euboea of natural causes later that same year, having named his student Antipater as his chief executor and leaving a will in which he asked to be buried next to his wife
Kant stated in the Critique of Pure Reason that with Aristotle logic reached its completion
Organon 

What is today called Aristotelian logic with its types of syllogism (methods of logical argument), Aristotle himself would have labelled "analytics"
The term "logic" he reserved to mean dialectics
Most of Aristotle's work is probably not in its original form, because it was most likely edited by students and later lecturers
The logical works of Aristotle were compiled into a set of six books called the Organon around 40 BC by Andronicus of Rhodes or others among his followers
The first three treatises form the core of the logical theory stricto sensu: the grammar of the language of logic and the correct rules of reasoning
The Rhetoric is not conventionally included, but it states that it relies on the Topics
Aristotle called it "first philosophy", and distinguished it from mathematics and natural science (physics) as the contemplative (theoretikē) philosophy which is "theological" and studies the divine
In Book VIII, he distinguishes the matter of the substance as the substratum, or the stuff of which it is composed
The formula that gives the components is the account of the matter, and the formula that gives the differentia is the account of the form
Immanent realism 

Like his teacher Plato, Aristotle's philosophy aims at the universal
Aristotle's ontology places the universal (katholou) in particulars (kath' hekaston), things in the world, whereas for Plato the universal is a separately existing form which actual things imitate
For Aristotle, "form" is still what phenomena are based on, but is "instantiated" in a particular substance
