The next easily identifiable major development in logic comes from Boole in 1847 with the creation of [[Boolean algebra]] and Boolean logic. In the 1870s, Peirce introduces a logic of quantifiers, followed by [[Gottlob Frege]]'s 1879 ''Begriffsschrift'', which contains the first complete formalization of the propositional calculus. Frege's work was developed in service of his logicist project, which was shown to be inconsistent by [[Bertrand Russell]] in 1903 with what is famously called [[Russell's paradox]]. In 1913 Russell and Whitehead published ''Principia Mathematica'', a landmark work that sought to define mathematics with first-order logic. | The next easily identifiable major development in logic comes from Boole in 1847 with the creation of [[Boolean algebra]] and Boolean logic. In the 1870s, Peirce introduces a logic of quantifiers, followed by [[Gottlob Frege]]'s 1879 ''Begriffsschrift'', which contains the first complete formalization of the propositional calculus. Frege's work was developed in service of his logicist project, which was shown to be inconsistent by [[Bertrand Russell]] in 1903 with what is famously called [[Russell's paradox]]. In 1913 Russell and Whitehead published ''Principia Mathematica'', a landmark work that sought to define mathematics with first-order logic. |