Philosophy › Socrates, Plato, Aristotle & the Axial Age
Aristotle
384–322 BC· Philosopher· Knowledge, logic & science
Well documentedSolid records, texts or physical evidence.
Greek philosopher and scientist, Plato's student and Alexander the Great's tutor, who systematized logic, biology, ethics and politics.
See it on the Philosophy map →The idea
Born in 384 BC at Stagira in northern Greece, son of a court doctor, he studied at Plato's Academy for 20 years. He tutored the young Alexander, then in 335 BC opened his own school in Athens, the Lyceum. Where Plato looked up to Forms, Aristotle looked closely at the world: he dissected animals, classified hundreds of species, and collected 158 city constitutions. He also defended slavery as natural and got much physics wrong, such as heavier objects falling faster.
Why it matters
For nearly 2,000 years he set the framework for science and philosophy in the Islamic world and Christian Europe, where he was simply 'the Philosopher'.
Legacy and sources
Perhaps a quarter to a third of his writings survive, mostly lecture notes edited in the 1st century BC; his polished dialogues are lost. Diogenes Laertius gives his life.
Still debated
How his views developed over time, and how far the surviving texts reflect his own editing rather than later compilers, are still debated.
Inside this (3)
Connections (9)
▸Zeno of Elea and his paradoxes of motion was analysed by AristotleWell documented
The connection
Zeno argued that motion is impossible: to cross a room you must first cross half, then half the rest, forever. Aristotle replied that time divides just as finely as distance, so infinitely many stages fit into a finite time, and that such infinities are only potential, never completed.
When and how
Aristotle's Physics, Books VI and VIII, written around 350–330 BC, roughly a century after Zeno posed the paradoxes.
How we know
Our main record of the paradoxes is Aristotle's own discussion of them; Zeno's book is lost.
Debates and open questions
Many mathematicians think the paradoxes were only fully resolved by 19th-century calculus and limits; some philosophers argue even that misses Zeno's point.
▸Plato taught AristotleWell documented
The connection
Aristotle arrived at Plato's Academy at 17 and stayed 20 years, first as student, then as teacher. He kept Plato's goal, real knowledge of universal truths, but grounded it in observation of this world. In his Ethics he notes that friends are dear, but truth must come first, even against Plato's ideas.
When and how
Athens, 367–347 BC. When Plato died, leadership of the Academy passed to his nephew Speusippus, and Aristotle left the city.
How we know
Ancient biographies, chiefly Diogenes Laertius, give the dates; Aristotle's works constantly discuss Plato's views, sometimes saying 'we' of the Platonists.
Debates and open questions
How much of Aristotle's system took shape while he was still a Platonist, and whether his break with Plato was early or gradual, is debated.
▸Plato's theory of Forms was rejected by AristotleWell documented
The connection
Aristotle argued that separate Forms explain nothing: positing a perfect Horse elsewhere doesn't tell us how real horses come to be. He also pressed the 'Third Man' regress. His alternative: form is real but exists only in things, as a statue's shape exists in its bronze, and is known by studying particular cases.
When and how
In his Metaphysics (Books I, VII and XIII–XIV) and other works, written after his 20 years in Plato's Academy, around 350–322 BC.
How we know
Aristotle's criticisms survive at length and name Plato and the Platonists directly; Plato's own Parmenides raises similar objections.
Debates and open questions
Whether Aristotle's critique fairly represents Plato, and whether his own 'forms in things' differ from Plato's as much as he claimed.
▸Aristotle founded Aristotle's logic and the syllogismWell documented
The connection
Aristotle claimed, with some justice, that no one before him had systematized reasoning. He introduced letters to stand for terms, defined the syllogism, and worked out which combinations of 'all', 'some' and 'no' premises guarantee a conclusion, creating the first formal logic.
When and how
Athens, around 350 BC, possibly while he was still teaching at Plato's Academy; set out in the Prior Analytics.
How we know
At the end of his Sophistical Refutations he says he found nothing earlier on reasoning to build on; the texts themselves survive.
Debates and open questions
Exactly when he developed the system is unknown, and whether Plato's method of division or Greek geometry gave him the idea is debated.
▸Aristotle proposed Aristotle's four causesWell documented
The connection
Aristotle saw earlier thinkers each grabbing one kind of explanation: the Presocratics stressed what things are made of, Plato stressed form. He combined them, added the maker and the purpose, and argued that a full scientific explanation of anything, from a statue to a heart, answers all four questions.
When and how
Athens, in the Physics and Metaphysics, probably written or revised at the Lyceum around 335–322 BC.
How we know
Physics Book II and Metaphysics Book I state the four causes and review how earlier philosophers had each caught only part of them.
Debates and open questions
Whether final causes in nature mean real purposes or just regular outcomes, like teeth growing in a way suited to chewing, is debated among Aristotle scholars.
▸Aristotle developed Virtue ethics and eudaimonia (Nicomachean Ethics)Well documented
The connection
Aristotle built virtue ethics on his view of human nature: every living thing has a characteristic function, and a human's is to use reason well. Doing that across a whole life, with good character, friends and enough means, is eudaimonia. He laid it out in lectures later edited as the Nicomachean Ethics.
When and how
Athens, at the Lyceum, around 335–322 BC; the title may honour his son Nicomachus, who possibly edited it, or his father of the same name.
How we know
The Nicomachean Ethics and the related Eudemian Ethics survive and are accepted as his; ancient catalogues of his works list them.
Debates and open questions
How the two Ethics relate, which came first, and whether his 'function argument' really supports his conclusions are long-standing debates.
▸Aristotle was fused with Christian theology by Thomas AquinasWell documented
The connection
Aquinas adopted Aristotle's logic, physics and ethics and his account of the soul as the form of the body, calling him simply 'the Philosopher'. He argued that Aristotle's reasoning, properly understood, supports Christian belief, while correcting points like the world's eternity, which he said reason could neither prove nor disprove.
When and how
Paris and Italy, about 1256–1274; Aquinas wrote commentaries on about a dozen of Aristotle's works, using new translations from the Greek by William of Moerbeke.
How we know
His Aristotle commentaries survive, and the Summa Theologiae quotes 'the Philosopher' on nearly every page.
Debates and open questions
Whether Moerbeke translated at Aquinas's request is uncertain; scholars debate how much Aquinas reshaped Aristotle, for example by adding the creator God Aristotle lacked.
▸Averroes (Ibn Rushd) wrote famous commentaries on AristotleWell documented
The connection
Averroes set out to recover the real Aristotle, stripping away Neoplatonic layers that Avicenna and others had mixed in. His long commentaries quote the text section by section and explain it line by line. Translated into Latin and Hebrew, they shaped how Europe read Aristotle for some 300 years.
When and how
Córdoba and Seville, about 1169–1195; reportedly begun after the philosopher Ibn Tufayl introduced him to the Almohad caliph Abu Yaqub Yusuf, who wanted Aristotle explained.
How we know
Dozens of commentaries survive in Arabic, Hebrew or Latin; Latin scholars called him simply 'the Commentator', and Renaissance editions printed his commentaries beside Aristotle's text.
Debates and open questions
The story of the caliph's request comes from a later report quoting a student; scholars also debate how 'pure' his Aristotle really was.
▸Greek-to-Arabic translation movement (House of Wisdom) translated the works of AristotleWell documented
The connection
Almost all of Aristotle's surviving works were translated into Arabic, often through Syriac, along with Greek commentaries on them. Aristotle became 'the First Teacher' in Arabic, and these versions, with Averroes' commentaries, later helped return his works to Latin Europe.
When and how
Baghdad, c. 800–1000: Hunayn ibn Ishaq, his son Ishaq, and the Christian logicians Abu Bishr Matta and Yahya ibn Adi.
How we know
Arabic manuscripts of the translations survive, and Ibn al-Nadim's Fihrist (987) names the translators of each work.
Debates and open questions
Aristotle's Politics apparently was never translated into Arabic; why is unclear.