| Philosophical Divide | Philosopher (Side A) | Philosopher (Side B) | Branch of Philosophy | Core Point of Disagreement |
|---|---|---|---|---|
| Change vs. Permanence | Heraclitus | Parmenides | Metaphysics | Is reality fundamentally flux or unchanging being? |
| World of Forms vs. Empirical Substances | Plato | Aristotle | Metaphysics / Epistemology | Whether intelligible Forms or sense particulars ground knowledge and existence |
| Rationalism vs. Empiricism | René Descartes | John Locke | Epistemology | Are ideas innate and grasped by reason, or derived from sensory experience? |
| Skepticism vs. Transcendental Critique | David Hume | Immanuel Kant | Epistemology / Metaphysics | Can certain knowledge of causation and metaphysics be secured? |
| State-of-Nature Pessimism vs. Optimism | Thomas Hobbes | Jean-Jacques Rousseau | Political Philosophy | Human nature and the extent/ground of political authority |
| Natural-Rights Liberalism vs. Authoritarian Contract | John Locke | Thomas Hobbes | Political Philosophy | Whether individuals retain inalienable rights against the sovereign |
| Separation of Powers vs. Legislative Primacy | John Locke | Montesquieu | Political Philosophy | Optimal institutional design: mixed monarchy/parliament vs. tripartite separation |
| Duty-Based Ethics vs. Consequentialism | Immanuel Kant | John Stuart Mill | Normative Ethics | Categorical duty vs. greatest-happiness principle as moral criterion |
| Pleasure vs. Virtue | Epicurus | Zeno of Citium (Stoics) | Ethics | Is the highest good tranquil pleasure or living virtuously in accord with nature? |
| Moderate Realism vs. Nominalism | Thomas Aquinas | William of Ockham | Metaphysics | Ontological status of universals (real in things vs. mere names) |
| Immaterialism vs. Materialism | George Berkeley | Baron d’Holbach | Metaphysics / Ontology | Whether matter exists independently of perception |
| Dialectical Idealism vs. Existential Individualism | G. W. F. Hegel | Søren Kierkegaard | Metaphysics / Existentialism | Primacy of collective Spirit vs. individual subjective truth |
| Central Planning vs. Spontaneous Order | Karl Marx | Friedrich Hayek | Political Philosophy / Economics | Mechanism of economic coordination and justice |
| Justice as Fairness vs. Entitlement Theory | John Rawls | Robert Nozick | Political Philosophy | Patterned distributive justice vs. historical ownership rights |
| Fixed Logical Meaning vs. Deconstruction | Early Ludwig Wittgenstein | Jacques Derrida | Philosophy of Language | Stability vs. indeterminacy of linguistic meaning |
| Idealism vs. Common-Sense Realism | George Berkeley | G. E. Moore | Metaphysics / Epistemology | Does esse est percipi, or do ordinary objects exist independently? |
| Mind–Body Dualism vs. Physicalism | René Descartes | J. J. C. Smart | Philosophy of Mind | Are mind and matter distinct substances or is everything physical? |
| Compatibilism vs. Hard Determinism | Daniel Dennett | Galen Strawson | Philosophy of Action | Can free will coexist with causal determinism? |
| Foundationalism vs. Coherentism | René Descartes | W. V. O. Quine | Epistemology | Must knowledge rest on indubitable foundations or web-like mutual support? |
| Virtue Ethics vs. Deontological Ethics | Aristotle | Immanuel Kant | Normative Ethics | Character-based excellence vs. universal moral duties |
| Ethical Egoism vs. Utilitarian Altruism | Ayn Rand | Peter Singer | Ethics | Should moral agents maximize self-interest or total welfare? |
| Logical Positivism vs. Philosophical Hermeneutics | A. J. Ayer | Hans-Georg Gadamer | Epistemology / Philosophy of Language | Verificationist meaning vs. historically situated interpretation |
| Scientific Realism vs. Instrumentalism | Karl Popper | Bas van Fraassen | Philosophy of Science | Do scientific theories aim at truth or merely empirical adequacy? |
| Essentialism vs. Anti-Essentialism (Gender) | Simone de Beauvoir | Judith Butler | Social Philosophy / Metaphysics | Are gender traits fixed essences or socially constructed performances? |
| Objective Truth vs. Post-modern Relativism | Karl Popper | Richard Rorty | Epistemology | Is truth an objective correspondence or a contingent, pragmatic construction? |
From the notebook