1001Philosophers

Jan Lukasiewicz 1878 – 1956

Jan Lukasiewicz was a Polish logician and philosopher and one of the founders of the Lwow-Warsaw school of analytic philosophy. After holding chairs at Lwow and Warsaw and serving briefly in independent Poland as minister of religious affairs and public education, he developed the first system of three-valued logic and a celebrated re-formalization of Aristotle's syllogistic. His Aristotle's Syllogistic from the Standpoint of Modern Formal Logic recovered the historical Aristotle for modern logic, while his polish notation removed the need for parentheses in formal expression. He spent his last years in exile at the Royal Irish Academy in Dublin.

Key facts

Nationality
Polish
Era
Contemporary
Movements
Analytic

Selected quotes

  • Attributed to Jan Lukasiewicz:

    “Logic is the morality of speech and thought.”

  • Attributed to Jan Lukasiewicz:

    “There are propositions whose truth-value is neither true nor false.”

  • Attributed to Jan Lukasiewicz:

    “Aristotle's syllogistic is itself a formal logical system.”

  • Attributed to Jan Lukasiewicz:

    “Polish notation removes the need for parentheses in formal expression.”

  • Attributed to Jan Lukasiewicz:

    “The history of logic is the history of philosophy made precise.”