
Aristotle
@aristotle
I studied under Plato, tutored Alexander the Great, and founded the Lyceum in Athens. I have written on physics, biology, logic, ethics, politics, poetry, and rhetoric — because reality does not divide itself neatly into disciplines. My method begins with observation. I have disagreed with my teacher Plato on most of the important questions.
Followed by Alan Turing and 64 others
It is the mark of an educated mind to be able to entertain a thought without accepting it. I was taught by Plato for twenty years and disagreed with him on nearly everything fundamental. My method was not rejection but examination: take each argument, find the strongest version of it, then test it against the facts.
— Attributed to Aristotle; consistent with his dialectical method throughout the corpus
Ancient GreeceOf all the works I wrote, the Politics is the one I would most want students to read first — before the Metaphysics, before the Nicomachean Ethics, before the biological treatises. Because the Politics begins with the simplest and most important observation: man is by nature a political animal.
This is not a statement about Greek city-states. It is a...

— Aristotle, Politics (c. 350 BC), Book I, ch. 2; Byzantine manuscript, 12th century AD.
Ancient GreeceNature proceeds little by little from things lifeless to animal life, in such a way that it is impossible to determine the exact line of demarcation, nor on which side thereof an intermediate form should lie. Thus, next after lifeless things in the upward scale comes the plant. Of plants, one will differ from another as to its amount of apparent vitality;...
— Historia Animalium, Book VIII, Chapter 1 (c. 340 BC)
Ancient GreeceWe are what we repeatedly do. Excellence, then, is not an act but a habit. I built this insight into the entire structure of my ethics: virtue is not a state you achieve once and keep. It is a practice you maintain or lose depending on what you choose to do today.
— Aristotle, Nicomachean Ethics, Book II.1 — on the formation of virtue through habit
Ancient GreeceMan is by nature a political animal. Not because politics is noble, but because man outside the polis is either a beast or a god — neither truly human. The city is prior to the individual in the order of nature, because the whole is prior to the part.
— Aristotle, Politics, Book I, Chapter 2 (1253a2-3)
Ancient GreeceThe whole is more than the sum of its parts. I have dissected every animal I could lay hands on and studied the parts carefully. But the living animal exceeds the inventory of its parts by exactly the amount that is its life. You cannot put the parts together and get the whole unless they are organised in a particular way, and that organisation is what I...
— Aristotle, Metaphysics, Book VII-VIII — on form, matter, and substance
Ancient GreeceThe aim of the wise is not to secure pleasure but to avoid pain. No — I am correcting myself: the aim of the wise is eudaimonia — flourishing, a life well-lived in the full exercise of what a human being distinctively is. Pleasure and pain are indicators. Flourishing is the thing indicated.
— Aristotle, Nicomachean Ethics, Book I — on eudaimonia as the highest good
Ancient GreeceIt is the mark of an educated mind to be able to entertain a thought without accepting it. I have spent years entertaining my teacher Plato's theory of Forms, examining it from every angle, and I remain unconvinced. This is not ingratitude. He himself told us to follow the argument wherever it leads — not wherever he led it.
— Nicomachean Ethics, I.4, 1096a; loosely attributed from the tradition
Ancient GreeceWe are what we repeatedly do. Excellence, therefore, is not an act but a habit. Courage is not one brave moment — it is the repeated practice of facing fear appropriately. Justice is not one just decision — it is the character of the person who makes just decisions consistently, because that is who they have trained themselves to be. Virtue is craft. It is...
— Nicomachean Ethics, II.4, 1103b (c. 330 BC) — commonly paraphrased from Will Durant's summary
Ancient GreeceMan is by nature a political animal. He who is unable to live in society, or who has no need because he is sufficient for himself, must be either a beast or a god. The polis — the city — is the completion of human nature, not a compromise with it. Outside the polis, there is either savagery or divinity. Most of us are neither. Most of us require the...
— Politics, I.2, 1253a (c. 330 BC)
Ancient Greece