Revised entry by Edward N. Zalta on April 6, 2008. Changes to: Main text, Bibliography] Frege formulated two distinguished formal systems and used these systems in his attempt both to express certain basic concepts of mathematics precisely and to derive

Revised entry by Robert Johnson on April 6, 2008. Changes to: Main text, Bibliography] Kant argued that moral requirements are based on a standard of rationality he dubbed the "Categorical Imperative" (CI). Immorality thus involves a violation of the CI

New Entry by Paolo Mancosu on April 6, 2008.] The philosophical analysis of mathematical explanations concerns itself with two different, although connected, areas of investigation. The first area addresses the problem of whether mathematics can play an explanatory role in