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(Sources for ideas, so far: Complete list of encyclopedia topics/A; The Dictionary of Cultural Literacy; try the Stanford Encyclopedia of Philosophy)
A priori and a posteriori knowledge -- A. N. Whitehead (or [Alfred North Whitehead]?) -- Abduction -- Abortion -- Absolute? -- Absolutism? -- Abstract -- [Academic Freedom]? -- Better: [academic freedom]? (l. c.) -- Accident? -- Account? (as a philosophical term, akin to "definition") -- Act? -- Action? -- Active? (vs. "passive," a technical term) -- Adam Smith -- Aesthetics -- [Affirmative action]? -- Affirming the consequent -- [Age of Enlightenment]? -- Agency? -- Agnosticism -- Albert Camus -- Alliance? -- Altruism -- Ambiguity -- [American Philosophical Association]? anthropomorphism -- Aristotle -- atheism -- axiom --
[Benedict Spinoza]? or Baruch Spinoza or [Baruch de Spinoza]? etc. -- Bertrand Russell -- Blaise Pascal -- Buddhist philosophy --
casuistry -- [Charles, Baron de Montesquieu]? -- Cicero -- [Cogito, ergo sum]? --
David Hume -- deduction -- deism -- determinism? -- dualism --
[Eastern philosophy]? -- [epistemic justification]? -- epistemology -- [ethical relativism]? -- ethics -- existentialism --
fatalism? -- Friedrich Nietzsche -- [free will]? --
[G. W. F. Hegel]? -- [greatest happiness principle]? --
hedonism -- humanism -- humanist -- humanities? --
I think, therefore I am -- idealism? -- Immanuel Kant -- [Indian philosophy]? -- induction -- inference? --
Jean-Jacques Rousseau -- John Locke -- John Stuart Mill -- justification? --
[law of noncontradiction]? -- [liberal arts]? -- logic -- Ludwig Wittgenstein --
[Man is the measure of all things]? -- Marxism -- materialism -- metaphysics -- [Michel de Montaigne]? -- monism -- monotheism -- mysticism? --
[natural law]? -- naturalism? -- nihilism -- noumenon? --
[On Liberty]? (by Mill) --
pantheism -- [Pascal's Wager]? -- [perfectability of man]? -- phenomenon? (a la Kant) -- philosopher -- philosopher-king? -- philosophes? -- philosophy -- physicalism -- Plato -- [Plato's Academy]? -- [Plato's Republic]? or [The Republic of Plato]? -- Platonism -- pluralism? -- polytheism -- positivism? (also: [logical empiricism]?; logical positivism) -- postulate -- pragmatism? -- Principia Mathematica -- Protagoras --
realism? -- relativism? -- Rene Descartes -- Republic --
Soren Kierkegaard -- scholasticism? -- semantics -- skepticism (or scepticism) -- [social contract]? -- [social contract theory]? -- solipsism? -- sophist? -- stoic? -- stoicism? -- [Summa Theologica]? -- superman or overman? or uebermensch? -- Symposium? (by Plato) --
tabula rasa -- Thales -- [The Prince]? (by Machiavelli) -- [The Social Contract]? (by Rousseau) -- [thing in itself]? or thing-in-itself? -- Thomas Aquinas -- Thomas Hobbes -- Thomism? -- [Thus Spake Zarathustra]? --
utilitarianism -- Utopia (by More) --
[Western philosophy]? -- William of Ockham --
[Zeno's Paradox]?