| Nicola Abbagnano | 1901 - 1990 |
| Peter Abelard | 1079 - 1142 |
| Robert Adamson | 1852 - 1902 |
| Mortimer Adler | 1902 - 2001 |
| Theodor Adorno | 1903 - 1969 |
| Samuel Alexander | 1859 - 1938 |
| Louis Althusser | 1918 - 1990 |
| William Ames | 1576 - 1633 |
| Anacharsis | |
| Anaxagoras | |
| Antisthenes | 444 BC - 371 BC |
| Aristotle | 384 BC - 322 BC |
| Raymond Aron | 1905 - 1983 |
| Sri Aurobindo | 1872 - 1950 |
| J. L. Austin | 1911 - 1960 |
| Avicenna | |
| Gaston Bachelard | 1884 - 1962 |
| Francis Bacon | 1919 - 1992 |
| Roger Bacon | 1214 - 1294 |
| Alain Badiou | 1937 |
| Alexander Bain | 1818 - 1903 |
| Pierre Bayle | 1647 - 1706 |
| Jonathan Bennett | 1930 |
| Jeremy Bentham | 1748 - 1832 |
| Nikolai Berdyaev | 1874 - 1948 |
| Henri Bergson | 1859 - 1941 |
| George Berkeley | 1685 - 1753 |
| Isaiah Berlin | 1909 - 1997 |
| Andrew Bernstein | |
| Annie Besant | 1847 - 1933 |
| Max Black | 1909 - 1988 |
| H. P. Blavatsky | 1831 - 1891 |
| Allan Bloom | 1930 - 1992 |
| Sissela Bok | 1934 |
| Francis Bowen | 1811 - 1890 |
| Robert Boyle | 1627 - 1691 |
| F. H. Bradley | 1846 - 1924 |
| John Bradshaw | |
| Norman O. Brown | 1913 - 2002 |
| Giordano Bruno | 1548 - 1600 |
| Paul Brunton | 1898 |
| Martin Buber | 1878 - 1965 |
| Kenneth Burke | 1897 - 1993 |
| Judith Butler | 1956 |
| Tommaso Campanella | 1568 - 1639 |
| Albert Camus | 1913 - 1960 |
| Thomas Carlyle | 1795 - 1881 |
| Rudolf Carnap | 1891 - 1970 |
| David Chalmers | 1966 |
| Pierre Charron | 1541 - 1603 |
| Sri Chinmoy | 1931 |
| Deepak Chopra | 1947 |
| Emile M. Cioran | 1911 - 1995 |
| Samuel Clarke | 1675 - 1729 |
| Robin G. Collingwood | 1889 - 1943 |
| Anthony Collins | 1676 - 1729 |
| Confucius | 551 BC - 479 BC |
| Victor Cousin | 1792 - 1867 |
| Marquis de Condorcet | 1743 - 1794 |
| Jean de La Bruyère | 1645 - 1696 |
| Michel de Montaigne | 1533 - 1592 |
| Baron de Montesquieu | 1689 - 1755 |
| Charles de Montesquieu | 1689 - 1755 |
| Charles de Secondat | 1689 - 1755 |
| Gilles Deleuze | 1925 - 1995 |
| Democritus | 460 BC - 370 BC |
| Daniel Dennett | 1942 |
| Jacques Derrida | 1930 - 2004 |
| Taisen Deshimaru | 1914 |
| John Dewey | 1859 - 1952 |
| Meister Eckhart | 1260 - 1328 |
| George Edward Moore | 1873 - 1958 |
| Jacques Ellul | 1912 - 1994 |
| Empedocles | 490 BC - 430 BC |
| Friedrich Engels | 1820 - 1895 |
| Epictetus | 55 - 135 |
| Epicurus | 341 BC - 271 BC |
| Desiderius Erasmus | 1466 - 1536 |
| William Ernest Hocking | 1873 - 1966 |
| Quintilian | 35 - 95 |
| Adam Ferguson | 1723 - 1816 |
| Marsilio Ficino | 1433 - 1499 |
| John Fiske | 1842 - 1901 |
| Charles Fourier | 1772 - 1837 |
| John Frame | 1939 |
| Henri Frédéric Amiel | 1821 - 1881 |
| Hans-Georg Gadamer | 1900 - 2002 |
| Nelson Goodman | 1906 - 1998 |
| Johann Gottlieb Fichte | 1762 - 1814 |
| Baltasar Gracian | 1601 - 1658 |
| Jean Guitton | |
| George Gurdjieff | 1872 - 1949 |
| Jurgen Habermas | 1929 |
| Ian Hacking | 1936 |
| Manly Hall | 1901 - 1990 |
| James Harrington | 1611 - 1677 |
| Henry Hazlitt | 1894 - 1993 |
| Martin Heidegger | 1889 - 1976 |
| Claud-Adrian Helvetius | 1715 - 1771 |
| Georg Henrik von Wright | 1916 - 2003 |
| George Henry Lewes | 1817 - 1878 |
| Heraclitus | 544 BC - 483 BC |
| Francis Herbert Hedge | 1846 - 1924 |
| George Herbert Mead | 1863 - 1931 |
| Eugen Herrigel | 1885 - 1955 |
| Thomas Hobbes | 1588 - 1679 |
| Sidney Hook | 1902 - 1989 |
| Cheri Huber | |
| David Hume | 1711 - 1776 |
| Jan Hus | 1369 - 1415 |
| Edmund Husserl | 1859 - 1938 |
| Francis Hutcheson | 1694 - 1747 |
| William Irwin Thompson | 1938 |
| Jean Jacques Rousseau | 1712 - 1778 |
| William James | 1842 - 1910 |
| Immanuel Kant | 1724 - 1804 |
| Walter Kaufmann | 1921 - 1980 |
| Mohammad Khatami | 1909 |
| Soren Kierkegaard | 1813 - 1855 |
| Saul Kripke | 1940 |
| Jiddu Krishnamurti | 1895 - 1986 |
| Paul Kurtz | 1925 |
| Imre Lakatos | 1922 - 1974 |
| Corliss Lamont | 1902 - 1995 |
| Susanne K. Langer | 1895 - 1985 |
| Laotse | |
| Gottfried Leibniz | 1646 - 1716 |
| John Locke | 1632 - 1704 |
| Ramana Maharshi | 1879 - 1950 |
| Maharishi Mahesh Yogi | 1917 |
| Maimonides | 1135 - 1204 |
| Nicolas Malebranche | 1638 - 1715 |
| Bernard Mandeville | 1670 - 1733 |
| Gabriel Marcel | 1889 - 1973 |
| Herbert Marcuse | 1898 - 1979 |
| Jacques Maritain | 1882 - 1973 |
| James Mark Baldwin | 1861 - 1934 |
| James Martineau | 1805 - 1900 |
| Karl Marx | 1818 - 1883 |
| George Matthew Adams | |
| George H. Mead | 1863 - 1931 |
| Alexander Meiklejohn | 1872 - 1964 |
| Mencius | 371 BC - 289 BC |
| Moses Mendelssohn | 1729 - 1786 |
| Nicholas Murray Butler | 1862 - 1947 |
| Nagarjuna | |
| Thomas Nagel | 1937 |
| Guru Nanak | 1469 - 1539 |
| Friedrich Nietzsche | 1844 - 1900 |
| Albert J. Nock | 1870 - 1945 |
| Michael Novak | 1933 |
| Robert Nozick | 1938 - 2002 |
| Michael Oakeshott | 1901 - 1990 |
| William of Occam | 1285 - 1349 |
| Diogenes | 412 BC - 323 BC |
| José Ortega y Gasset | 1883 - 1955 |
| Blaise Pascal | 1623 - 1662 |
| Charles Péguy | 1873 - 1914 |
| Leonard Peikoff | 1909 |
| Philo | 20 BC - 40 AD |
| Robert M. Pirsig | 1928 |
| Plotinus | 205 - 270 |
| Plutarch | 46 - 120 |
| Karl Popper | 1902 - 1994 |
| Richard Price | 1723 - 1791 |
| Protagoras | 481 BC - 411 BC |
| Hilary Putnam | 1926 |
| Morris Raphael Cohen | 1880 - 1947 |
| Thomas Reid | 1710 - 1796 |
| Ernest Renan | 1823 - 1892 |
| Paul Ricoeur | 1913 - 2005 |
| Richard Rorty | 1931 |
| Josiah Royce | 1855 - 1916 |
| Bertrand Russell | 1872 - 1970 |
| George Santayana | 1863 - 1952 |
| Jean-Paul Sartre | 1905 - 1980 |
| Max Scheler | 1874 - 1928 |
| Moritz Schlick | 1882 - 1936 |
| Arthur Schopenhauer | 1788 - 1860 |
| John Searle | 1932 |
| Amartya Sen | 1933 |
| Hu Shih | 1891 - 1962 |
| Henry Sidgwick | 1838 - 1900 |
| Peter Singer | 1946 |
| Swami Sivananda | 1887 - 1963 |
| Georges Sorel | 1847 - 1922 |
| Herbert Spencer | 1820 - 1903 |
| Oswald Spengler | 1880 - 1936 |
| Baruch Spinoza | 1632 - 1677 |
| Lysander Spooner | 1808 - 1887 |
| Rudolf Steiner | |
| Max Stirner | 1806 - 1856 |
| Leo Strauss | 1899 - 1973 |
| John Stuart Mill | 1806 - 1873 |
| Tao Te Ching | |
| Pierre Teilhard de Chardin | 1881 - 1955 |
| Thales | 624 BC - 546 BC |
| Theophrastus | |
| Kerry Thornley | 1938 - 1998 |
| Chogyam Trungpa | 1939 - 1987 |
| Abraham Tucker | 1705 - 1774 |
| Chuang Tzu | 369 BC - 286 BC |
| Lao Tzu | |
| Sun Tzu | |
| Raoul Vaneigem | 1934 |
| John Venn | 1834 - 1923 |
| Giambattista Vico | 1668 - 1744 |
| Pir Vilayat Khan | 1916 |
| Friedrich von Schelling | 1775 - 1854 |
| Alan Watts | 1915 - 1973 |
| Alan W. Watts | 1915 - 1973 |
| Simone Weil | 1909 - 1943 |
| Otto Weininger | 1880 - 1903 |
| William Whewell | 1794 - 1866 |
| Benjamin Whichcote | 1609 - 1683 |
| Ken Wilber | 1949 |
| Georg Wilhelm Friedrich Hegel | 1770 - 1831 |
| Dallas Willard | 1935 |
| Ludwig Wittgenstein | 1889 - 1951 |
| Chauncey Wright | 1830 - 1875 |
| Xenocrates | 396 BC - 314 BC |
| Xenophanes | 570 BC - 480 BC |
| Dogen Zenji | 1200 - 1253 |
| Citium Zeno | 335 BC - 264 BC |
| Xi Zhi | 1130 - 1200 |
| Xun Zi | 310 BC - 237 BC |
| Zhuang Zi | 369 BC - 286 BC |