» History of Philosophy
- Gournay, Marie Le Jars de
- Abelard, Peter
- Abu Ya’qub al-Sijistani
- Academy, The
- Active Powers
- Addams, Jane
- Adorno, Theodor
- Aenesidemus
- Agamben, Giorgio
- al-Kirmani, Hamid al-Din
- Al-Shahrastānī
- Alexander Polyhistor
- Alexander, Samuel
- Analytic Philosophy
- Anaxagoras
- Anaxarchus
- Anaximander
- Anaximenes
- Ancient Greek Philosophy
- Ancient Greek Skepticism
- Angélique Arnauld
- Anscombe, G. E. M.
- Anselm
- Antisthenes
- Aquinas, Thomas
- Aquinas: Metaphysics
- Aquinas: Moral Philosophy
- Aquinas: Political Philosophy
- Aquinas’ Philosophical Theology
- Arcesilaus
- Arendt, Hannah
- Aristippus
- Aristotle
- Aristotle: Biology
- Aristotle: Ethics
- Aristotle: Logic
- Aristotle: Metaphysics
- Aristotle: Motion and its Place in Nature
- Aristotle: Poetics
- Aristotle: Politics
- Arnauld, Agnès
- Augustine
- Avicenna (Ibn Sina)
- Aztec Philosophy
- Bacon, Francis
- Bacon, Roger
- Beattie, James
- Beauvoir, Simone de
- Beccaria, Cesare
- Bentham, Jeremy