The InteLex Past Masters database The philosophers contains correspondence from the most important English-language philosophers.
Transcribed from: Berkeley, George, 1685-1753 Letters, vol. 8 of The works of George Berkeley, Bishop of Cloyne London, New York : T. Nelson, 1948-1957 Edited by A.A. Luce and T.E. Jessop.
Transcribed from: Bradley, F. H. (Francis Herbert), 1846-1924 Notebooks, papers & correspondence of F.H. Bradley Charlottesville: InteLex Corporation, 2004 Edited by Carol Keene.
Transcribed from: Ferguson, Adam, 1723-1816 The correspondence of Adam Ferguson London: Pickering & Chatto, 1995 Edited by Vincenzo Merolle, consulting editor Kenneth Wellesley, with an introduction by Jane B. Fagg.
Transcribed from: Hume, David, 1711-1776 The letters of David Hume London: Oxford University Press, 1932 Edited by J.Y.T Greig.
Transcribed from: Hume, David, 1711-1776 New letters London: Oxford University Press, 1954 Edited by Raymond Klibansky and Ernest C. Mossner.
Transcribed from: Sidgwick, Henry, 1838-1900 The complete works and select correspondence of Henry Sidgwick 2d Edition Charlottesville: InteLex Corporation, 1996 Edited by Bart Schultz.
Transcribed from: Smith, Adam, 1723-1790 Correspondence, vol. 6 of The Glasgow Edition of the works and correspondence of Adam Smith Oxford: Clarendon Press, 1987.
Transcribed from: Spencer, Herbert, 1820-1903 Life and letters of Herbert Spencer London: Methuen, 1908 Edited by David Duncan.