172 ideas
| 11461 | 323 (roughly): Euclid wrote 'Elements', summarising all of geometry [PG] |
| 11390 | 1000 (roughly): Upanishads written (in Sanskrit); religious and philosophical texts [PG] |
| 11391 | 750 (roughly): the Book of Genesis written by Hebrew writers [PG] |
| 11392 | 586: eclipse of the sun on the coast of modern Turkey was predicted by Thales of Miletus [PG] |
| 11395 | 570: Anaximander flourished in Miletus [PG] |
| 11396 | 563: the Buddha born in northern India [PG] |
| 11398 | 540: Lao Tzu wrote 'Tao Te Ching', the basis of Taoism [PG] |
| 11400 | 529: Pythagoras created his secretive community at Croton in Sicily [PG] |
| 11403 | 500: Heraclitus flourishes at Ephesus, in modern Turkey [PG] |
| 11404 | 496: Confucius travels widely, persuading rulers to be more moral [PG] |
| 11408 | 472: Empedocles persuades his city (Acragas in Sicily) to become a democracy [PG] |
| 11412 | 450 (roughly): Parmenides and Zeno visit Athens from Italy [PG] |
| 11414 | 445: Protagoras helps write laws for the new colony of Thurii [PG] |
| 11417 | 436 (roughly): Anaxagoras is tried for impiety, and expelled from Athens [PG] |
| 11421 | 427: Gorgias visited Athens as ambassador for Leontini [PG] |
| 11425 | 399: Socrates executed (with Plato absent through ill health) [PG] |
| 11432 | 387 (roughly): Plato returned to Athens, and founded the Academy [PG] |
| 11433 | 387 (roughly): Aristippus the Elder founder a hedonist school at Cyrene [PG] |
| 11440 | 367: the teenaged Aristotle came to study at the Academy [PG] |
| 11443 | 360 (roughly): Diogenes of Sinope lives in a barrel in central Athens [PG] |
| 11445 | 347: death of Plato [PG] |
| 11454 | 343: Aristotle becomes tutor to 13 year old Alexander (the Great) [PG] |
| 11456 | 335: Arisotle founded his school at the Lyceum in Athens [PG] |
| 11459 | 330 (roughly): Chuang Tzu wrote his Taoist book [PG] |
| 11465 | 322: Aristotle retired to Chalcis, and died there [PG] |
| 11468 | 307 (roughly): Epicurus founded his school at the Garden in Athens [PG] |
| 11470 | 301 (roughly): Zeno of Citium founded Stoicism at the Stoa Poikile in Athens [PG] |
| 11483 | 261: Cleanthes replaced Zeno as head of the Stoa [PG] |
| 11486 | 229 (roughly): Chrysippus replaced Cleanthes has head of the Stoa [PG] |
| 11492 | 157 (roughly): Carneades became head of the Academy [PG] |
| 11509 | 85: most philosophical activity moves to Alexandria [PG] |
| 11513 | 78: Cicero visited the stoic school on Rhodes [PG] |
| 11516 | 60 (roughly): Lucretius wrote his Latin poem on epicureanism [PG] |
| 11528 | 65: Seneca forced to commit suicide by Nero [PG] |
| 11531 | 80: the discourses of the stoic Epictetus are written down [PG] |
| 11535 | 170 (roughly): Marcus Aurelius wrote his private stoic meditations [PG] |
| 11537 | -200 (roughly): Sextus Empiricus wrote a series of books on scepticism [PG] |
| 11541 | 263: Porphyry began to study with Plotinus in Rome [PG] |
| 11545 | 310: Christianity became the official religion of the Roman empire [PG] |
| 11549 | 387: Ambrose converts Augustine to Christianity [PG] |
| 11555 | 523: Boethius imprisoned at Pavia, and begins to write [PG] |
| 11557 | 529: the emperor Justinian closes all the philosophy schools in Athens [PG] |
| 11558 | 622 (roughly): Mohammed writes the Koran [PG] |
| 11559 | 642: Arabs close the philosophy schools in Alexandria [PG] |
| 11560 | 910 (roughly): Al-Farabi wrote Arabic commentaries on Aristotle [PG] |
| 11562 | 1015 (roughly): Ibn Sina (Avicenna) writes a book on Aristotle [PG] |
| 11564 | 1090: Anselm publishes his proof of the existence of God [PG] |
| 11566 | 1115: Abelard is the chief logic teacher in Paris [PG] |
| 11573 | 1166: Ibn Rushd (Averroes) wrote extensive commentaries on Aristotle [PG] |
| 11581 | 1266: Aquinas began writing 'Summa Theologica' [PG] |
| 11586 | 1280: after his death, the teaching of Aquinas becomes official Dominican doctrine [PG] |
| 11591 | 1328: William of Ockham decides the Pope is a heretic, and moves to Munich [PG] |
| 17916 | 1347: the Church persecutes philosophical heresies [PG] |
| 11593 | 1470: Marsilio Ficino founds a Platonic Academy in Florence [PG] |
| 11596 | 1513: Machiavelli wrote 'The Prince' [PG] |
| 11599 | 1543: Copernicus publishes his heliocentric view of the solar system [PG] |
| 11601 | 1580: Montaigne publishes his essays [PG] |
| 11607 | 1600: Giordano Bruno was burned at the stake in Rome [PG] |
| 11613 | 1619: Descartes's famous day of meditation inside a stove [PG] |
| 11614 | 1620: Bacon publishes 'Novum Organum' [PG] |
| 11619 | 1633: Galileo convicted of heresy by the Inquisition [PG] |
| 11623 | 1641: Descartes publishes his 'Meditations' [PG] |
| 11626 | 1650: death of Descartes, in Stockholm [PG] |
| 11627 | 1651: Hobbes publishes 'Leviathan' [PG] |
| 11633 | 1662: the Port Royal Logic is published [PG] |
| 11634 | 1665: Spinoza writes his 'Ethics' [PG] |
| 11643 | 1676: Leibniz settled as librarian to the Duke of Brunswick [PG] |
| 11649 | 1687: Newton publishes his 'Principia Mathematica' [PG] |
| 11652 | 1690: Locke publishes his 'Essay' [PG] |
| 11654 | 1697: Bayle publishes his 'Dictionary' [PG] |
| 11659 | 1713: Berkeley publishes his 'Three Dialogues' [PG] |
| 11666 | 1734: Voltaire publishes his 'Philosophical Letters' [PG] |
| 11667 | 1739: Hume publishes his 'Treatise' [PG] |
| 11675 | 1762: Rousseau publishes his 'Social Contract' [PG] |
| 11682 | 1781: Kant publishes his 'Critique of Pure Reason' [PG] |
| 11683 | 1785: Reid publishes his essays defending common sense [PG] |
| 11687 | 1798: the French Revolution [PG] |
| 11694 | 1807: Hegel publishes his 'Phenomenology of Spirit' [PG] |
| 11701 | 1818: Schopenhauer publishes his 'World as Will and Idea' [PG] |
| 11710 | 1840: Kierkegaard is writing extensively in Copenhagen [PG] |
| 11713 | 1843: Mill publishes his 'System of Logic' [PG] |
| 11715 | 1848: Marx and Engels publis the Communist Manifesto [PG] |
| 11717 | 1859: Darwin publishes his 'Origin of the Species' [PG] |
| 11721 | 1861: Mill publishes 'Utilitarianism' [PG] |
| 11724 | 1867: Marx begins publishing 'Das Kapital' [PG] |
| 11733 | 1879: Peirce taught for five years at Johns Hopkins University [PG] |
| 17907 | 1879: Frege invents predicate logic [PG] |
| 17909 | 1892: Frege's essay 'Sense and Reference' [PG] |
| 17908 | 1884: Frege publishes his 'Foundations of Arithmetic' [PG] |
| 11735 | 1885: Nietzsche completed 'Thus Spake Zarathustra' [PG] |
| 17911 | 1888: Dedekind publishes axioms for arithmetic [PG] |
| 11740 | 1890: James published 'Principles of Psychology' [PG] |
| 11742 | 1895 (roughly): Freud developed theories of the unconscious [PG] |
| 11745 | 1900: Husserl began developing Phenomenology [PG] |
| 11746 | 1903: Moore published 'Principia Ethica' [PG] |
| 11747 | 1904: Dewey became professor at Columbia University [PG] |
| 17910 | 1908: Zermelo publishes axioms for set theory [PG] |
| 11752 | 1910: Russell and Whitehead begin publishing 'Principia Mathematica' [PG] |
| 11756 | 1912: Russell meets Wittgenstein in Cambridge [PG] |
| 11762 | 1921: Wittgenstein's 'Tractatus' published [PG] |
| 11765 | 1927: Heidegger's 'Being and Time' published [PG] |
| 11768 | 1930: Frank Ramsey dies at 27 [PG] |
| 11770 | 1931: Gödel's Incompleteness Theorems [PG] |
| 11773 | 1933: Tarski's theory of truth [PG] |
| 11783 | 1942: Camus published 'The Myth of Sisyphus' [PG] |
| 11784 | 1943: Sartre's 'Being and Nothingness' [PG] |
| 11787 | 1945: Merleau-Ponty's 'Phenomenology of Perception' [PG] |
| 17918 | 1947: Carnap published 'Meaning and Necessity' [PG] |
| 11794 | 1950: Quine's essay 'Two Dogmas of Empiricism' [PG] |
| 17917 | 1953: Wittgenstein's 'Philosophical Investigations' [PG] |
| 17919 | 1956: Place proposed mind-brain identity [PG] |
| 11804 | 1962: Kuhn's 'Structure of Scientific Revolutions' [PG] |
| 17921 | 1967: Putnam proposed functionalism of the mind [PG] |
| 11808 | 1971: Rawls's 'A Theory of Justice' [PG] |
| 11810 | 1972: Kripke publishes 'Naming and Necessity' [PG] |
| 11813 | 1975: Singer publishes 'Animal Rights' [PG] |
| 17920 | 1975: Putnam published his Twin Earth example [PG] |
| 11820 | 1986: David Lewis publishes 'On the Plurality of Worlds' [PG] |
| 192 | Only one thing can be contrary to something [Plato] |
| 9955 | Contextual definitions replace a complete sentence containing the expression [George/Velleman] |
| 10031 | Impredicative definitions quantify over the thing being defined [George/Velleman] |
| 10098 | The 'power set' of A is all the subsets of A [George/Velleman] |
| 10099 | The 'ordered pair' <a, b>, for two sets a and b, is the set {{a, b},{a}} [George/Velleman] |
| 10101 |
Cartesian Product A x B: the set of all ordered pairs |
| 10103 | Grouping by property is common in mathematics, usually using equivalence [George/Velleman] |
| 10104 | 'Equivalence' is a reflexive, symmetric and transitive relation; 'same first letter' partitions English words [George/Velleman] |
| 10096 | Even the elements of sets in ZFC are sets, resting on the pure empty set [George/Velleman] |
| 10097 | Axiom of Extensionality: for all sets x and y, if x and y have the same elements then x = y [George/Velleman] |
| 10100 | Axiom of Pairing: for all sets x and y, there is a set z containing just x and y [George/Velleman] |
| 17900 | The Axiom of Reducibility made impredicative definitions possible [George/Velleman] |
| 10109 | ZFC can prove that there is no set corresponding to the concept 'set' [George/Velleman] |
| 10108 | As a reduction of arithmetic, set theory is not fully general, and so not logical [George/Velleman] |
| 10111 | Asserting Excluded Middle is a hallmark of realism about the natural world [George/Velleman] |
| 10129 | A 'model' is a meaning-assignment which makes all the axioms true [George/Velleman] |
| 10105 | Differences between isomorphic structures seem unimportant [George/Velleman] |
| 10119 | Consistency is a purely syntactic property, unlike the semantic property of soundness [George/Velleman] |
| 10126 | A 'consistent' theory cannot contain both a sentence and its negation [George/Velleman] |
| 10120 | Soundness is a semantic property, unlike the purely syntactic property of consistency [George/Velleman] |
| 10127 | A 'complete' theory contains either any sentence or its negation [George/Velleman] |
| 10106 | Rational numbers give answers to division problems with integers [George/Velleman] |
| 10102 | The integers are answers to subtraction problems involving natural numbers [George/Velleman] |
| 10107 | Real numbers provide answers to square root problems [George/Velleman] |
| 9946 | Logicists say mathematics is applicable because it is totally general [George/Velleman] |
| 10125 | The classical mathematician believes the real numbers form an actual set [George/Velleman] |
| 17899 | Second-order induction is stronger as it covers all concepts, not just first-order definable ones [George/Velleman] |
| 10128 | The Incompleteness proofs use arithmetic to talk about formal arithmetic [George/Velleman] |
| 17902 | A successor is the union of a set with its singleton [George/Velleman] |
| 10133 | Frege's Theorem shows the Peano Postulates can be derived from Hume's Principle [George/Velleman] |
| 10130 | Set theory can prove the Peano Postulates [George/Velleman] |
| 10089 | Talk of 'abstract entities' is more a label for the problem than a solution to it [George/Velleman] |
| 10131 | If mathematics is not about particulars, observing particulars must be irrelevant [George/Velleman] |
| 10092 | In the unramified theory of types, the types are objects, then sets of objects, sets of sets etc. [George/Velleman] |
| 10094 | The theory of types seems to rule out harmless sets as well as paradoxical ones. [George/Velleman] |
| 10095 | Type theory has only finitely many items at each level, which is a problem for mathematics [George/Velleman] |
| 17901 | Type theory prohibits (oddly) a set containing an individual and a set of individuals [George/Velleman] |
| 10114 | Bounded quantification is originally finitary, as conjunctions and disjunctions [George/Velleman] |
| 10134 | Much infinite mathematics can still be justified finitely [George/Velleman] |
| 10123 | The intuitionists are the idealists of mathematics [George/Velleman] |
| 10124 | Gödel's First Theorem suggests there are truths which are independent of proof [George/Velleman] |
| 190 | If asked whether justice itself is just or unjust, you would have to say that it is just [Plato] |
| 20185 | The most important things in life are wisdom and knowledge [Plato] |
| 20184 | The only real evil is loss of knowledge [Plato] |
| 191 | Everything resembles everything else up to a point [Plato] |
| 10110 | Corresponding to every concept there is a class (some of them sets) [George/Velleman] |
| 203 | Courage is knowing what should or shouldn't be feared [Plato] |
| 202 | No one willingly and knowingly embraces evil [Plato] |
| 193 | Some things are good even though they are not beneficial to men [Plato] |
| 197 | Some pleasures are not good, and some pains are not evil [Plato] |
| 200 | People tend only to disapprove of pleasure if it leads to pain, or prevents future pleasure [Plato] |
| 188 | Socrates did not believe that virtue could be taught [Plato] |
| 204 | Socrates is contradicting himself in claiming virtue can't be taught, but that it is knowledge [Plato] |
| 189 | If we punish wrong-doers, it shows that we believe virtue can be taught [Plato] |