Primary Sources – Philosophy During and Around the 20th Century The Life of the Mind by Hannah Arendt Language, Truth, and Logic by A.J. Ayer The Problem of Knowledge by A.J. Ayer Selected Writings of Jean Baudrillard The Ethics of Ambiguity by Simone de Beauvoir An Introduction to Metaphysics by Henri Bergson Matter and Memory by Henri Bergson Time and Free Will by Henri Bergson I and Thou by Martin Buber The Myth of Sisyphus and Other Essays by Albert Camus The Rebel by Albert Camus Language and Mind by Noam Chomsky The God Delusion by Richard Dawkins Nietzsche and Philosophy by Gilles Deleuze What is Philosophy? by Gilles Deleuze & Félix Guattari Consciousness Explained by Daniel Dennett Darwin’s Dangerous Idea by Daniel Dennett The Intentional Stance by Daniel Dennett Speech and Phenomena & Other Essays by Jacques Derrida Dissemination by Jacques Derrida Of Grammatology by Jacques Derrida Against Method by Paul Feyerabend The Archaeology of Knowledge & The Discourse on Language by Michel Foucault The Order of Things by Michel Foucault Selected Writings of Mahatma Gandhi The End of Faith by Sam Harris The Condition of Postmodernity by David Harvey God is Not Great by Christopher Hitchens Logical Investigations by Edmund Husserl Does Consciousness Exist? by William James What Pragmatism Means by William James The Varieties of Religious Experience by William James The Will to Believe by William James Reason and Existenz by Karl Jaspers Last Writings: Nothingness and the Religious Worldview by Nishida Kitarō The Levinas Reader edited by Sáun Hand The Self-Overcoming of Nihilism by Keiji Nishitani Philosophical Explanations by Robert Nozick Man Has No Nature by José Ortega y Gasset The Language Instinct by Steven Pinker Word and Object by W.V. Quine The Virtue of Selfishness by Ayn Rand Contingency, Irony, and Solidarity by Richard Rorty Philosophy and the Mirror of Nature by Richard Rorty In Praise of Idleness by Bertrand Russell Mysticism and Logic: And Other Essays by Bertrand Russell On Denoting by Bertrand Russell The Problems of Philosophy by Bertrand Russell The Concept of Mind by Gilbert Ryle Being and Nothingness by Jean-Paul Sartre Critique of Dialectical Reason: Volume I by Jean-Paul Sartre Critique of Dialectical Reason: Volume II (Unfinished) by Jean-Paul Sartre Existentialism is a Humanism by Jean-Paul Sartre My View of the World (Excerpt) by Erwin Schrödinger Athens and Jerusalem by Lev Shestov The Ego and His Own by Max Stirner The Courage to Be by Paul Tillich The Eternal Now by Paul Tillich Weak Thought edited by Gianni Vattimo and Pier Aldo Rovatti The Wisdom of Insecurity by Alan Watts Process and Reality by Alfred North Whitehead Philosophical Investigations by Ludwig Wittgenstein Tractatus Logico-Philosophicus by Ludwig Wittgenstein Note: You can find 135 free philosophy e-books and free online philosophy courses at Open Culture. Project Gutenberg and Internet Archive both host vast libraries of e-books for free to the public.