Piotr Lukowski, winner of the Alfred Tarski Logic Prize for Poland 2025

[jean-yves beziau]

We are glad to announce the winner of the Alfred Tarski Logic Prize for Poland 2025:

https://www.uni-log.org/alfred-tarski-prize-of-logic-2025.html

Piotr Lukowski, Jagiellonian University,  Krakow, Poland

Title of the paper: Universal Principle of Consistency

Abstract: Around 300 BCE, a debate emerged concerning the truth conditions of conditional propositions—a debate that, to this day, has not culminated in a formulation genuinely satisfying to philosophers. Nevertheless, the material implication proposed by Philo the Dialectician achieved considerable prominence, despite its evident divergence from the patterns of ordinary human reasoning. Its success may be attributed, at least in part, to its formal simplicity. It is now widely acknowledged, however, that Philo’s implication is not the long-sought representation of implication that would faithfully capture intuitive reasoning. This recognition is underscored by the vigorous development of formal logic, much of which has been driven by the search for a notion of implication that aligns more closely with our cognitive intuitions. As Susan Haack once remarked, a true solution to a philosophical problem is recognizable by the deep internal conviction it evokes regarding its adequacy. Arguably, none of the proposed definitions of implication to date have elicited such conviction, not even among their originators—hence, the search continues.

The present study introduces a principle that appears to underlie human reasoning regardless of its subject matter—whether one is engaged in mathematical theorizing or reflecting on matters of everyday life, the same logical structure, the same inferential tool, seems to be consistently employed. We propose that this tool is the Universal Principle of Consistency (UPC), or, in its strengthened form, the Strong Universal Principle of Consistency (SUPC). This universal principle is derived from the definitions of two content-based implications: the hyperintensional content inclusion implication and the intensional content relationship implication. Both appear to align closely with the structure of ordinary reasoning, both resonate with the logical intuitions of the Ancients—particularly Chrysippus and Diodorus—and both prove effective in domains such as legal and mathematical reasoning. Moreover, they offer a precise account of key pragmatic phenomena, including presupposition and implicatures.
If the proposal put forward here is accurate, it may be argued that it brings to a close the debate that began in antiquity. 

This paper will be published in the journal Logica Universalis 

and presented at the 8th UNILOG in Cusco at the 3rd World Logic Prizes Contest

https://sites.google.com/view/unilog2025/logic-prizes

Jean-Yves Beziau

Federal University of Rio de Janeiro

https://philpeople.org/profiles/jean-yves-beziau

Project

 A PRIZE OF LOGIC IN EVERY COUNTRY !   

https://www.uni-log.org/logic-prize-world