 Titles have been given in their original language, followed in the case of pieces originally in Polish by the title of any published English translation where one exists, or by our English translation where none does. The bibliography of Łukasiewicz’s published writings is not complete, since a large number of his published pieces consist of one- or two-page summaries or abstracts of talks given at various venues, as was the Polish practice of the time. Of this kind, only those which are important for Łukasiewicz’s development or the exposition of his views have been included. Translations into languages other than English have not been included, with one exception, the 1910 monograph on Aristotle.