List of philosophers (I–Q)

Philosophers (and others important in the history of philosophy), listed alphabetically:

Note: This list has a minimal criterion for inclusion and the relevance to philosophy of some individuals on the list is disputed.

I

• Iamblichus (c. 245 – c. 325 AD)^[b][d][e]
• Yahya ibn Adi (893–974)^[d]
• Ibn Arabi (1164–1240)^[b][d][e]
• Ibn ar-Rawandi (827–911)^[d]
• Ibn Bajjah (or Avempace) (died 1138)^[a][b][d][e]
• Ibn Daud (or Rabad I or Avendauth, or John of Spain) (1110–1180)^[a][d][e]
• Abraham ibn Ezra (1092/3–1167)^[d][e]
• Moses ibn Ezra (1070–1138)^[d]
• Ibn Falaquera (1223–1290)^[d][e]
• Solomon Ibn Gabirol (1021–1058)^{[a][b][c][d][e]}
• Ibn Hazm (994–1069)^[d]
• Ibn Kammuna (1215–1284)^[d][e]
• Ibn Khaldun (1332–1406)^[a][b][c][d]
• Ibn Masarra (883–931)^[d]
• Ibn Miskawayh (940–1030)^[a][d]
• Bahya ibn Paquda (1040–1110)^[b][d]
• Ibn Sabin (1217–1268)^[d]
• Ibn Taymiya (1263–1328)^[d]
• Samuel ibn Tibbon (c. 1165 – 1232)^[e]
• Ibn Tufail (1110–1185)^[a][b][d]
• Joseph ibn Tzaddik (c. 1149)^[b][d]
• Ivan Aleksandrovich Il'in (1883–1954)^[a][b][d]
• Evald Vassilievich Ilyenkov (1924–1979)^[d]
• Immanuel the Roman (c. 1270 – c. 1330)^[d]
• Roman Ingarden (1893–1970)^{[a][b][c][d][e]}
• William Ralph Inge (1860–1954)^[b][d]
• José Ingenieros (1877–1925)^[b]
• Nae Ionescu (1890–1940)^[b]
• Muhammad Iqbal (1877–1938)^[b][c][d]
• Luce Irigaray (born 1930)^[a][b][c][d]
• Terence Irwin (born 1947)^[c]
• Isocrates (436–338 BC)^[a]
• Isaac of Stella (1105–1177)^[b][d]
• Isaac Israeli (c. 850–950)^[b][d][e]
• Ito Jinsai (1627–1705)^[b][d]
• Vyacheslav Ivanovich Ivanov (1866–1949)^[b]

J

• Jesus of Nazareth (4 BC – AD 30 or 33)
• Frank Jackson (born 1943)^[c]
• Friedrich Heinrich Jacobi (1743–1819)^{[a][b][c][d][e]}
• Franz Jakubowski (1912–1970)
• James of Viterbo (1255–1308)^[d][e]
• Henry James Sr. (1811–1882)^[b]
• William James (1842–1910)^{[a][b][c][d][e]}
• Fredric Jameson (born 1934)
• Vladimir Jankélévitch (1903–1985)^[b]
• Anselm Jappe (born 1962)
• Karl Jaspers (1883–1969)^{[a][b][c][d][e]}
• Jayarāśi Bhaṭṭa (fl. c. 800)^[e]
• James Hopwood Jeans (1877–1946)^[b]
• Thomas Jefferson (1743–1826)^[b][c][d][e]
• Richard C. Jeffrey (1926–2002)^[c]
• William Stanley Jevons (1835–1882)^[a][b][c][e]
• Rudolf von Jhering (1818–1892)^[d]
• Jinul (or Chinul) (1158–1210)^[b][d]
• Joachim of Fiore (1135–1201)^[a][b][d]
• Friedrich Jodl (1849–1914)^[b]
• John of Damascus (c. 676–749)^[a][b][d]
• John of Jandun (1280–1328)^[b][d]
• John of La Rochelle (1190–1245)^[b][d]
• John of Mirecourt (c. 1345)^[b][d]
• John of Paris (1260–1306)^[b][d]
• John of Salisbury (c. 1115–1180)^[a][b][d][e]
• John of St. Thomas (or Jean Poinsot) (1589–1644)^[a][b][d]
• John of the Cross (1542–1591)^[b]
• Alexander Bryan Johnson (1786–1867)^[b][d]
• Samuel Johnson (1649–1703)^[d]
• Samuel Johnson (1696–1772)^[b]
• Samuel Johnson (1709–1784)^[b][c][d]
• William Ernest Johnson (1858–1931)^[a][c]
• Constance Jones (1848–1922)^[e]
• Jørgen Jørgensen (1894–1969)^[c]
• Théodore Simon Jouffroy (1796–1842)^[b]
• Judah ben Moses of Rome (orJudah Romano) (1292–1330)^[d]
• Carl Jung (1875–1961)^[a][b][c][d]
• Ernst Jünger (1895–1998)^[b]
• Joachim Jungius (1587–1657)^[b][d]
• Justinian I (483–565)^[d]
• Al-Juwayni (1028–1085)^[d]

K

• Franz Kafka (1883–1924)^[b]
• Kaibara Ekiken (1630–1740)^[b][d]
• Kang Youwei (1858–1927)^[a]
• Milan Kangrga (1923–2008)
• Immanuel Kant (1724–1804)^{[a][b][c][d][e]}
• Kao Tzu (c. 420 – 350 BC)^[a]
• David Kaplan (born 1933)^[b][c]
• Mordecai Kaplan (1881–1983)^[d]
• Kojin Karatani (born 1941)
• Nikolai Ivanovich Kareev (1850–1931)^[b]
• Lev Platonovich Karsavin (1882–1952)^[b]
• Joseph Kaspi (1279–1340) ^[e]
• Walter Kaufmann (1921–1980)^[b]
• Karl Kautsky (1854–1938)^[b][c][d]
• Khedrup Gelek Pelzang (1385–1438)^[d]
• Konstantin Kavelin (1818–1885)^[b]
• Bartholomew Keckermann (1571–1609)^[d]
• Hans Kelsen (1881–1973)^[b][c][d]
• Norman Kemp Smith (1872–1958)^[d]
• Anthony Kenny (born 1931)^[c]
• Johannes Kepler (1571–1630)^[a][b][d][e]
• John Maynard Keynes (1883–1946)^[a][b][c][d]
• Hermann Graf Keyserling (1880–1946)^[b]
• Aleksey Khomyakov (1804–1860)^[b]
• Søren Kierkegaard (1813–1855)^{[a][b][c][d][e]}
• Richard Kilvington (1302–1361)^[a][b][d][e]
• Robert Kilwardby (1215–1279)^[a][b][d][e]
• Jaegwon Kim (1934–2019)^[a][b][c]
• Al-Kindi (801–873)^{[a][b][c][d][e]}
• Martin Luther King Jr. (1929–1968)^[b]
• Athanasius Kircher (1602–1680)
• Ivan Kireevsky (1806–1856)^[b]
• Patricia Kitcher (born 1948)^[b]
• Ludwig Klages (1872–1956)^[b]
• Heinrich von Kleist (1777–1811)^[a][b]
• William Calvert Kneale (1906–1990)^[c]
• Martin Knutzen (1713–1751)^[b][d]
• Ko Hung (4th century)^[a]
• Kurt Koffka (1886–1941)^[b]
• Wolfgang Köhler (1887–1967)^[a][b]
• Alexandre Kojève (1902–1968)^[d]
• Leszek Kołakowski (1927–2009)
• Alejandro Korn (1860–1936)^[b][c]
• Karl Korsch (1886–1961)
• Karel Kosík (1926–2003)
• Tadeusz Kotarbiński (1886–1981)^[a][b][c][d]
• Alexandre Koyre (1892–1964)^[d]
• Aleksei Aleksandrovich Kozlov (1831–1901)^[b]
• Karl Kraus (1874–1936)^[c]
• Karl Christian Friedrich Krause (1781–1832)^[a][b][d]
• Georg Kreisel (1923–2015)^[c]
• Saul Kripke (born 1940)^[a][b][c][d]
• Jiddu Krishnamurti (1895–1986)
• Uppaluri Gopala Krishnamurti (1918–2007)
• Julia Kristeva (born 1941)^[a][b][c][d]
• Nachman Krochmal (1785–1840)^[d]
• Leopold Kronecker (1823–1891)^[d]
• Peter Kropotkin (1842–1921)^[a][b][c][d]
• Felix Krueger (1874–1948)^[b]
• Thomas Samuel Kuhn (1922–1996)^{[a][b][c][d][e]}
• Kūkai (774–835)^[c][d][e]
• Kuki Shūzō (1888–1941)^[d]
• Oswald Külpe (1862–1915)^[b]
• Kumārila Bhaṭṭa (fl. roughly 700)^[e]
• Kumazawa Banzan (1619–1691)^[b][d]
• Kuo Hsiang (or Guoxiang) (died c. 312)^[a]
• Robert Kurz (1943–2012)

L

• Ernst Laas (1837–1885)^[b]
• Lucien Laberthonnière (1860–1932)^[b]
• Jean de La Bruyère (1645–1696)^[b]
• Jacques Lacan (1901–1981)^[a][b][c][e]
• Jules Lachelier (1832–1918)^[b][d]
• Ernesto Laclau (1935–2014)
• Philippe Lacoue-Labarthe (1940–2007)^[d]
• Pierre Laffitte (1823–1903)^[a]
• Louis de La Forge (1632–1666)^[a][d][e]
• Imre Lakatos (1922–1974)^[b][c][d][e]
• André Lalande (1867–1964)^[b]
• Jean-Baptiste Lamarck (1744–1829)^[b][c]
• Johann Heinrich Lambert (1728–1777)^[a][b][d]
• Hughes Felicité Robert de Lamennais (1752–1854)^[b]
• Julien Offray de La Mettrie (1709–1751)^[a][b][c][d]
• François de La Mothe Le Vayer (1588–1672)^[b]
• Ludwig Landgrebe (1902–1992)^[b]
• Friedrich Albert Lange (1828–1875)^[a][b][d][e]
• Susanne Langer (1895–1985)^[b][c][d]
• Lao Zi (or Lao Tzu) (4th century BC)^[a][b][c][e]
• Isaac La Peyrère (1596–1676)^[a][b]
• Pierre-Simon Laplace (1749–1827)^[a][b][c]
• Ivan Ivanovich Lapshin (1870–1952)^[b]
• François de La Rochefoucauld (1613–1680)^[b]
• Pierre Laromiguière (1756–1837)^[b]
• Abdullah Laroui (born 1935)^[b]
• Ferdinand Lassalle (1825–1864)^[b][d]
• Bruno Latour (born 1947)
• Johann Kaspar Lavater (1741–1801)^[b]
• Louis Lavelle (1883–1951)^[b]
• Antoine Lavoisier (1743–1794)^[b]
• Peter Lavrovitch Lavrov (1823–1900)^[b][d]
• William Law (1686–1761)^[b][d]
• Jean Le Clerc (1657–1737)^[b][d]
• Michèle Le Dœuff (born 1948)^[c][d]
• Henri Lefebvre (1901–1991)^[d]
• Jacques Lefèvre d'Étaples (c. 1455–c. 1536)^[e]
• Claude Lefort (1924–2010)
• Antoine Le Grand (1629–1699)^[d][e]
• Keith Lehrer (born 1936)^[b][c]
• Gottfried Leibniz (1646–1716)^{[a][b][c][d][e]}
• Yeshayahu Leibowitz (1903–1994)^[d][e]
• Vladimir Lenin (1870–1924)^[a][b][c][d]
• Leonardo da Vinci (1452–1519)^[b]
• Konstantin Nikolaevich Leont'ev (1831–1891)^[b][d]
• Aleksei N. Leontiev (1903–1979)
• Giacomo Leopardi (1798–1837)^[b]
• Jules Lequier (1814–1862)^[a][b]
• Pierre Leroux (1798–1871)^[a]
• Edouard Louis Emmanuel Julien Le Roy (1870–1954)^[b][d]
• René Le Senne (1882–1954)^[b]
• Stanisław Leśniewski (1886–1939)^{[a][b][c][d][e]}
• Gotthold Ephraim Lessing (1729–1781)^[a][b][c][d]
• Leucippus (5th century BC)^{[a][b][c][d][e]}
• Emmanuel Levinas (1906–1995)^{[a][b][c][d][e]}
• Claude Lévi-Strauss (1908–2009)^[c][d]
• Lucien Lévy-Bruhl (1857–1939)^[b][c]
• Kurt Lewin (1890–1947)^[a]
• Clarence Irving Lewis (1883–1964)^{[a][b][c][d][e]}
• C. S. Lewis (1898–1963)^[a][b][d]
• David Kellogg Lewis (1941–2001)^{[a][b][c][d][e]}
• Li Ao (722–841)^[a][b]
• Liang Qichao (or Liang Ch'i-ch'ao) (1873–1929)^[a]
• Liang Sou-ming (1893–1988)^[a]
• Georg Christoph Lichtenberg (1742–1799)^[b][c][d]
• Arthur Liebert (1878–1946)^[b]
• Otto Liebmann (1840–1912)^[b]
• Liezi (or Lieh Tzu) (c. 440 – c. 360& BC)^[a]
• Mikhail Lifshitz (1905–1983)
• Linji Yixuan (or Lin Chi) (c. 810 – 867)^[d]
• Carl Linnaeus (1707–1778)^[d]
• Theodor Lipps (1851–1914)^[b]
• Justus Lipsius (1547–1606)^[b][d][e]
• Émile Littré (1801–1881)^[b]
• Liu Shaoqi (orLiu Shao-ch'i) (1898–1969)^[a]
• Liu Tsung-chou (or Ch'i-shan) (1578–1645)^[a]
• Genevieve Lloyd (born 1941)^[b]
• Karl Nickerson Llywelyn (1893–1962)^[d]
• Ramon Llull (1235–1315)^[a][b][d][e]
• Alain LeRoy Locke (1885–1954)^[e]
• John Locke (1632–1704)^{[a][b][c][d][e]}
• Alfred Loisy (1857–1940)^[b][d]
• Peter Lombard (c. 1100 – 1160)^[a][b][d]
• Bernard Lonergan (1904–1984)^[d]
• Pseudo-Longinus (1st century)^[a][b]
• Leo Mikhailovich Lopatin (1855–1920)^[b]
• Frédéric Lordon (born 1962)
• Paul Lorenzen (1915–1995)^[d]
• Aleksei Fedorovich Losev (1893–1988)^[b][d]
• Nicholas Onufrievich Lossky (1870–1965)^[b][d]
• Domenico Losurdo (1941–2018)
• Juri Lotman (1922–1993)^[b]
• Hermann Lotze (1817–1881)^{[a][b][c][d][e]}
• Arthur O. Lovejoy (1873–1962)^[b][c]
• Leo Löwenthal (1900–1993)
• Michael Löwy (born 1938)
• John R. Lucas (1929–2020)^[c]
• Lucian (c. 120 – c. 180)^[b][d]
• Lucretius (c. 99 – 55 BC)^{[a][b][c][d][e]}
• Lu Jiuyuan (or Lu Xiangshan, or Lu Chiu-yuan, or Tzu-ching, or Ts'un-chai) (1139–1193)^[a][b][d]
• Georg Lukács (1885–1971)^{[a][b][c][d][e]}
• Jan Łukasiewicz (1878–1956)^{[a][b][c][d][e]}
• Anatoliy Lunacharskiy (1875–1933)^[b]
• Martin Luther (1483–1546)^{[a][b][c][d][e]}
• Rosa Luxemburg (1871–1919)^[d]
• William Lycan (born 1945)^[c]
• Jean-François Lyotard (1924–1998)^{[a][b][c][d][e]}

M

• Catharine Macaulay (1731–1791)^[e]
• Ernst Mach (1838–1916)^{[a][b][c][d][e]}
• Niccolò Machiavelli (1469–1527)^{[a][b][c][d][e]}
• Alasdair MacIntyre (born 1929)^[a][b][c][d]
• John Leslie Mackie (1917–1981)^[b][c]
• Madhava (died 1386)^[d]
• Shri Madhvacharya (1238–1317)^[a][c][d]
• Mahavira (599–527 BC)^[a][d]
• Salomon Maimon (or Salomon ben Joshua) (1753–1800)^[a][b][d][e]
• Abraham ben Moses Maimonides (or Abraham ben Maimon) (1186–1237)^[d]
• Maimonides (or Rambam) (1135–1204)^{[a][b][c][d][e]}
• Maine de Biran (1766–1824)^[b][c][d]
• John Major (or John Mair) (1467–1550)^[b][c][d]
• Errico Malatesta (1853–1932)
• Norman Malcolm (1911–1990)^[a][b][c]
• Nicolas Malebranche (1638–1715)^{[a][b][c][d][e]}
• Ernst Mally (1879–1944)^[e]
• André Malraux (1901–1976)^[b]
• Thomas Malthus (1766–1834)^[b]
• Merab Mamardashvili (1930–1990)^[b][d]
• Bernard de Mandeville (1670–1733)^[b][d]
• Mani (3rd century)^[b]
• Karl Mannheim (1893–1947)^[a][b][c]
• Henry Longueville Mansel (1820–1871)^[a][b]
• Mao Zedong (or Mao Tse-tung) (1893–1976)^[a]
• Gabriel Marcel (1887–1973)^{[a][b][c][d][e]}
• Marcion (110–160)^[b]
• Ruth Barcan Marcus (1921–2012)^[a][b][c]
• Herbert Marcuse (1898–1979)^[a][c][d][e]
• Joseph Maréchal (1878–1944)^[b]
• Juan de Mariana (1536–1624)^[a][b]
• Julián Marías (1914–2005)^[b]
• José Carlos Mariátegui (1894–1930)
• Lucrezia Marinella (1571–1653)^[e]
• Ruy Mauro Marini (1932–1997)
• Jacques Maritain (1882–1973)^{[a][b][c][d][e]}
• Gaius Marius Victorinus (4th century)^[d]
• Mihailo Marković (1923–2010)
• Svetozar Marković (1846–1875)^[b]
• Odo Marquard (1928–2015)
• Marsilius of Inghen (1330–1396)^[a][b][d][e]
• Marsilius of Padua (or Marsiglio or Marsilio dei Mainardine) (1270–1342)^[a][b][c][d]
• Roger Marston (1235–1303)^[b][d]
• José Martí (1853–1895)
• Charles B. Martin (1924–2008)^[c]
• Harriet Martineau (1802–1876)^[d]
• James Martineau (1805–1900)^[a][b][c]
• Piero Martinetti (1872–1943)^[b]
• Anton Marty (1847–1914)^[b][e]
• Marko Marulić (1450–1524)^[b]
• Karl Marx (1818–1883)^{[a][b][c][d][e]}
• Tomáš Masaryk (1850–1937)^[b][c][d]
• Damaris Cudworth Masham (1659–1708)^[a][d][e]
• Cotton Mather (1663–1728)^[b]
• Matthew of Aquasparta (1238–1302)^[b][d]
• Paul Mattick (1904–1981)^[b]
• Pierre Louis Maupertuis (1698–1759)^[b]
• Fritz Mauthner (1849–1923)^[d]
• James Clerk Maxwell (1831–1879)^[a][b][d]
• Ernst Mayr (1904–2005)
• James McCosh (1811–1894)^[a][b]
• William McDougall (1871–1938)^[a][b]
• John McDowell (born 1942)^[b][c]
• Evander Bradley McGilvary (1864–1953)^[b]
• Colin McGinn (born 1950)^[c]
• John Ellis McTaggart (1866–1925)^{[a][b][c][d][e]}
• George Herbert Mead (1863–1931)^{[a][b][c][d][e]}
• Bartolomé de Medina (1527–1580)^[a]
• Franz Mehring (1846–1919)^[b]
• Georg Friedrich Meier (1718–1777)^[b]
• Quentin Meillassoux (born 1967)
• Friedrich Meinecke (1862–1954)^[b][d]
• Alexius Meinong (1853–1920)^{[a][b][c][d][e]}
• Philipp Melanchthon (1497–1560)^[b][d]
• Melissus of Samos (late 5th century BC)^[a][b][c][d]
• D. Hugh Mellor (1938–2020)^[c]
• Menasseh Ben Israel (1604–1657)^[b]
• Mencius (or Meng K'o or Meng-tzu or Mengzi) (372–289 BC)^{[a][b][c][d][e]}
• Gregor Mendel (1822–1884)^[a]
• Moses Mendelssohn (1729–1786)^{[a][b][c][d][e]}
• Susan Mendus (born 1951)
• Désiré-Joseph Mercier (1851–1926)^[a][b]
• Maurice Merleau-Ponty (1908–1961)^{[a][b][c][d][e]}
• George merill (1867–1928)
• Marin Mersenne (1588–1648)^[a][b][d][e]
• Jean Meslier (1664–1729)^[b]
• Judah Messer Leon (c. 1425 – c. 1495)^[d]
• István Mészáros (1930–2017)
• Emile Meyerson (1859–1933)^[b][c][d]
• Conyers Middleton (1683–1750)^[b]
• Mary Midgley (1919–2018)
• Nikolai Konstantinovich Mikhailovskii (1842–1904)^[b][d]
• Miki Kiyoshi (1897–1945)^[b][d]
• Mikyo Dorje (or Mi bskyod rdo rje) (1507–1554)^[d]
• Gaston Milhaud (1858–1918)^[b]
• James Mill (1773–1836)^{[a][b][c][d][e]}
• John Stuart Mill (1806–1873)^{[a][b][c][d][e]}
• John Millar (1735–1801)^[d]
• Dickinson Miller (1868–1963)^[b]
• Ruth Millikan (born 1933)^[b][c]
• John Milton (1608–1674)^[b]
• Minagawa Kien (1734–1807)^[b]
• Mir Damad (or Mir Mohammad Baqer Esterabadi) (died 1631)^[d]
• Miura Baien (1723–1789)^[b]
• Jacob Moleschott (1822–1893)^[b]
• Luis de Molina (1535–1600)^[a][b][c][d]
• Enrique Molina Garmendia (1871–1962)^[b]
• Lord Monboddo (or James Burnett) (1714–1799)^[d]
• Richard Montague (1930–1971)^[b][d]
• William Pepperell Montague (1873–1953)^[b]
• Michel de Montaigne (1533–1592)^{[a][b][c][d][e]}
• Baron de Montesquieu (1689–1755)^[a][b][d][e]
• Edmund Montgomery (1835–1911)^[b]
• G. E. Moore (1873–1958)^{[a][b][c][d][e]}
• Henry More (1614–1687)^[a][b][d][e]
• Thomas More (1478–1535)^[a][b][e]
• C. Lloyd Morgan (1852–1936)^[b]
• Lewis H. Morgan (1818–1881)^[b]
• Thomas Morgan (died 1743)^[b]
• Karl Philipp Moritz (1756–1793)^[b]
• Edgar Morin (born 1921)
• Gaetano Mosca (1858–1941)^[a][b]
• Motoori Norinaga (1730–1801)^[d]
• Emmanuel Mounier (1905–1950)^[b]
• Mou Tsung-san (1909–1995)^[a]
• Mozi (or Mo Tzu, or Mo Ti, or Micius) (c. 470 – c. 390 BC)^[a][b][d]
• David Ibn Merwan Al-Mukammas (or Daud Ibn Marwan al-Muqammas or David ha-Bavli) (died 937)^[b][d]
• Mulla Sadra (1571–1640)^[b][c][d][e]
• Iris Murdoch (1919–1999)^[b][c]
• Muro Kyuso (1658–1734)^[b]
• Arthur Edward Murphy (1901–1962)^[b]
• Musonius Rufus (1st century)^[b][d]

N

• Arne Næss (1912–2009)^[c][d]
• Nagarjuna (c. 200 CE)^{[a][b][c][d][e]}
• Ernest Nagel (1901–1985)^[a][b][c][d]
• Thomas Nagel (born 1937)^[a][b][c][d]
• Nahmanides (1194–1270)^[d]
• Jacques-André Naigeon (1738–1810)^[b]
• Toju Nakae (1608–1648)^[b]
• Jean-Luc Nancy (1940–2021)^[d]
• Hossein Nasr (born 1933)^[b]
• Paul Gerhard Natorp (1854–1924)^[b][e]
• Márcio Bilharinho Naves (born 1952)
• Sergey Nechayev (1847–1882)
• Alexander Neckham (1157–1217)^[d]
• Antonio Negri (1933–2023)
• Leonard Nelson (1882–1927)^[b]
• Nemesius of Emesa (fl. c. 400)^[a][b][d]
• John von Neumann (1903–1957)^[a][b][c][d]
• Otto Neurath (1882–1945)^[b][c][d][e]
• John Henry Newman (1801–1890)^[a][b][d]
• Isaac Newton (1642–1727)^{[a][b][c][d][e]}
• Nichiren (1222–1282)^[d]
• Nicholas of Autrecourt (c. 1300 – 1369)^{[a][b][c][d][e]}
• Nicholas of Cusa (1401–1464)^{[a][b][c][d][e]}
• Christoph Friedrich Nicolai (1733–1811)^[b]
• Pierre Nicole (1625–1695)^[b]
• H. Richard Niebuhr (1894–1962)^[d]
• Reinhold Niebuhr (1892–1971)^[b][d]
• Friedrich Nietzsche (1844–1900)^{[a][b][c][d][e]}
• Agostino Nifo (1470–1538)^[d]
• Nishi Amane (1829–1897)^[b][d]
• Nishida Kitaro (1870–1945)^[b][c][d][e]
• Nishitani Keiji (1900–1990)^[c][d]
• Kwame Nkrumah (1909–1972)^[c]
• John Norris (1657–1711)^[b][d][e]
• Novalis (1772–1801)^[a][b][e]
• Robert Nozick (1938–2001)^[a][b][c][d]
• Numenius of Apamea (2nd century)^[a][b][d][e]
• Martha Nussbaum (born 1947)^[a][b][c]
• Anders Nygren (1890–1978)^[d]

O

• Michael Oakeshott (1901–1990)^{[a][b][c][d][e]}
• William of Ockham (c. 1285–1349)^{[a][b][c][d][e]}
• Ogyū Sorai (1666–1728)^[b][d]
• Lorenz Oken (1779–1851)^[b][d]
• Karl Olivecrona (1897–1980)^[d]
• Peter Olivi (1248–1298)^[a][b][d][e]
• Olympiodorus the Younger (495–570)^[e]
• John Wood Oman (1860–1939)^[b][d]
• Michel Onfray (born 1959)
• Onora O'Neill (born 1941)^[c]
• Nicole Oresme (1320–1382)^[b][d][e]
• Origen of Alexandria (c. 182–c. 251)^[a][b][d][e]
• Isaac Orobio de Castro (1617–1687)^[b]
• Hans Christian Ørsted (1777–1851)
• José Ortega y Gasset (1883–1955)^{[a][b][c][d][e]}
• Peter Osborne (philosopher) (born 1958)
• Wilhelm Ostwald (1853–1932)^[b]
• James Oswald (1703–1793)^[d]
• Rudolf Otto (1869–1937)^[b][d]
• Richard Overton (died c. 1665)^[d]
• Gwilyn Ellis Lane Owen (1922–1982)^[b][c][d]

P

• Thomas Paine (1737–1809)^{[a][b][c][d][e]}
• Menyhért Palágyi (1859–1924)^[b]
• William Paley (1743–1805)^[a][b][d]
• Elihu Palmer (1764–1806)^[b]
• Panaetius (c. 185 – c. 110 BC)^[b][d]
• Antonie Pannekoek (1873–1960)
• Wolfhart Pannenberg (1928–2014)^[b]
• David Papineau (born 1947)^[c]
• Giovanni Papini (1881–1956)^[b]
• Paracelsus (1493–1541)^[a][b][d]
• Vilfredo Pareto (1848–1923)^[b]
• Derek Parfit (1942–2017)^[a][b][c]
• Theodore Parker (1810–1860)^[b]
• Parmenides (5th century BC)^{[a][b][c][d][e]}
• Blaise Pascal (1623–1662)^[a][b][d][e]
• John Arthur Passmore (1914–2004)^[d]
• Valentino Annibale Pastore (1868–1956)^[b]
• Patañjali (2nd century BC)^[d]
• Walter Pater (1839–1904)^[b]
• Jan Patočka (1907–1977)^[d]
• Francesco Patrizi da Cherso (or Franciscus Patritius) (1529–1597)^[b][d][e]
• Akos Pauler (1876–1933)^[b]
• Linus Pauling (1901–1994)^[b]
• Paul of Venice (1369–1429)^[a][b][d][e]
• Friedrich Paulsen (1846–1908)^[b]
• Ivan Pavlov (1849–1936)^[b]
• Christopher Peacocke (born 1950)^[c]
• Giuseppe Peano (1858–1932)^[b][c]
• David Pears (1921–2009)^[c]
• Karl Pearson (1857–1936)^[b]
• John Peckham (died 1292)^[b][d]
• Benjamin Peirce (1809–1880)^[e]
• Charles Sanders Peirce (1839–1914)^{[a][b][c][d][e]}
• Pelagius (c. 360 – c. 435)^[b][c]
• William Penbygull (died 1420)^[e]
• Thomas Percival (1740–1804)^[a]
• Ralph Barton Perry (1876–1957)^[a][b][c]
• Johann Heinrich Pestalozzi (1746–1827)^[b]
• Peter of Auvergne (13th century)^[d]
• Peter of Spain (13th century; usually identified with Pope John XXI)^{[a][b][c][d][e]}
• Richard Stanley Peters (1919–2011)^[c]
• Petrarch (1304–1374)^[b][c][d]
• Leon Petrazycki (1867–1931)^[d]
• Joane Petrizi (12th century)^[e]
• Branislav Petronijević (1875–1954)^[b]
• Petar II Petrović-Njegoš (1813–1851)^[b]
• Joseph Petzoldt (1862–1929)^[b]
• Alexander Pfänder (1870–1941)^[b]
• Philip the Chancellor (1160–1236)^[d][e]
• Philo Judaeus of Alexandria (20 BC–40 AD)^{[a][b][c][d][e]}
• Philo of Larissa (1st century BC)^[d][e]
• Philo the Dialectician (c. 300 BC)^[c][d]
• Philodemus of Gadara (1st century BC)^[b][d][e]
• Philolaus of Croton (c. 480 – c. 405 BC)^[a][b][d][e]
• Philo of Larissa (154 – 84 BC)^[b]
• Philo of Megara (fl. 300 BC)^[b]
• John Philoponus (early 6th century)^{[a][b][c][d][e]}
• Jean Piaget (1896–1980)^[a][b][d]
• Giovanni Pico della Mirandola (1463–1494)^{[a][b][c][d][e]}
• Dimitri Pisarev (1840–1868)^[b]
• Max Planck (1858–1947)^[b][c][d]
• Alvin Plantinga (born 1932)^[a][b][c]
• Plato (c. 427 – c. 347 BC)^{[a][b][c][d][e]}
• Georgi Plekhanov (1856–1918)^[a][b][c][d]
• Helmuth Plessner (1892–1985)^[b]
• Gemistus Pletho (c. 1355 – c. 1452)^[b]
• Plotinus (died 270)^{[a][b][c][d][e]}
• Gottfried Ploucquet (1716–1790)^[b]
• Mestrius Plutarch of Chaeronia (c. 45 – c. 120)^[b][d][e]
• Henri Poincaré (1854–1912)^{[a][b][c][d][e]}
• Karl Polanyi (1886–1964)
• Michael Polanyi (1891–1976)^[d]
• Pietro Pomponazzi (1462–1525)^{[a][b][c][d][e]}
• Alexander Pope (1688–1744)^[b]
• Karl Popper (1902–1994)^{[a][b][c][d][e]}
• Josef Popper-Lynkeus (1838–1921)^[b]
• Porphyry (c. 232 – c. 304)^{[a][b][c][d][e]}
• Giambattista della Porta (c. 1535–1615)^[e]
• Noah Porter (1811–1892)^[b]
• Posidonius (c. 135 – 51 BC)^[b][d]
• Richard Posner (born 1939)^[b]
• Emil Leon Post (1897–1954)^[d]
• Moishe Postone (1942–2018)
• Robert Joseph Pothier (1699–1772)^[d]
• Nicos Poulantzas (1936–1979)
• François Poullain de la Barre (1647–1723)^[e]
• Roscoe Pound (1870–1964)^[d]
• Caio Prado Júnior (1907–1990)
• Costanzo Preve (1943–2013)
• Henry Habberley Price (1899–1984)^[c]
• Richard Price (1723–1791)^{[a][b][c][d][e]}
• Harold Arthur Prichard (1871–1947)^[a][c][d][e]
• Joseph Priestley (1733–1804)^[a][b][c][d]
• Andrew Seth Pringle-Pattison (1856–1931)^[b]
• Arthur Prior (1914–1969)^[b][d][e]
• Proclus (412–487)^[b][c][d][e]
• Prodicus (c. 450 – 399 BC)^[b][d]
• Protagoras (c. 481 – 420 BC)^[b][c][d][e]
• Pierre-Joseph Proudhon (1809–1865)^[a][b][c][d]
• Marcel Proust (1871–1922)^[b]
• Pseudo-Dionysius the Areopagite (5th century)^[b][d][e]
• Pseudo-Grosseteste (13th century)^[b][d]
• Ptolemy (c. 85 – c. 165)^[d]
• Samuel Pufendorf (1632–1694)^[a][b][d]
• Isaac ben Joseph ibn Pulgar (14th century)^[e]
• Hilary Putnam (1926–2016)^[a][b][c][d]
• Pyrrho (c. 360 – c. 270)^{[a][b][c][d][e]}
• Pythagoras (582 – 496 BC)^{[a][b][c][d][e]}
• Paul Heyman (1965 - Present)

Q

• Antero de Quental (1842–1891)
• Ismael Quiles (1906–1993)
• W. V. O. Quine (1908–2000)^{[a][b][c][d][e]}
• Anthony Quinton (1925–2010)^[c]