revised and augmented throughout by Sir Henry Stuart Jones, with the assistance of Roderick McKenzie, Clarendon Press, Oxford, UK, 1940. Online, perseus.tufts.edu. Butchvarov, Panayot, Skepticism About the External World (Oxford University Press, 1998). Richard Hönigswald, Die Skepsis in Philosophie und Wissenschaft, 1914, new edition (ed. and introduction by Christian Benne and Thomas Schirren), Göttingen: Edition Ruprecht, 2008, Keeton, Morris T., "skepticism", pp. 277–278 in Dagobert D. Runes (ed.), Dictionary of Philosophy, Littlefield, Adams, and Company, Totowa, NJ, 1962. Webster's New International Dictionary of the English Language, Second Edition, Unabridged, W.A. Neilson, T.A. Knott, P.W. Carhart (eds.), G. & C. Merriam Company, Springfield, MA, 1950. Further reading External links "Most Scientific Papers are Probably Wrong" , New Scientist, 30 August 2005 Classical Skepticism by Peter Suber "Outstanding skeptics of the 20th century" – Skeptical Inquirer magazine Epistemological theories Philosophical methodology Philosophical schools and traditions Psychological attitude Scientific method Doubt