Inedita, vol. 1: Logic. Part I

This volume of Kazimierz Twardowski’s logical inedita begins with a simple and beautiful (undated) text “Logic as a science of the truth of propositions” and ends with his (also undated) short and insightful remarks under the common – originating from the editor – title “Scientific authority”.

The core of the volume is the texts of Twardowski’s university lectures from 1895-1926, delivered by him at the University of Lvov. They belong mainly to the branches of logic, which he called “elementary” (“theoretical”) and “methodological” (“practical”), respectively, and to syllogistic. Lectures on syllogistic are interesting, also today, because they belong to the most extensive exposition of this branch of logic in the Polish literature. Their value is increased by the fact that the often very complex issues discussed in them are illustrated with carefully selected, instructive, and at the same time unconventional examples. On the other hand, lectures on the theory of inductive research – originating, importantly, from the academic year 1895/1896 – turned out to be an important inspiration for research on induction and probability theory, as well as on the status of laws in science, later undertaken by representatives of the Lvov-Warsaw School.

A historian of logic would be particularly interested in two texts by Twardowski, published here for the first time. The first of them is a surviving fragment of a work, probably from around 1920, in which Twardowski makes a distinction between discovery and justification, so important for 20th-century methodology. The second of them is Twardowski’s (again, only fragmentary) remarks on the attempts at the “algebraic” reform of formal logic undertaken at the turn of the 20th century, in which he emphasizes certain common shortcomings of these attempts.