‪Éternité et développement : la question du temps logique chez Leśniewski‪

The problem of time has both tormented and nourished philosophy since its beginnings. To address this problem, we propose to engage in a metaphysical reading of S. Leśniewski's texts. This reading will allow us to explain certain main properties of logical time. In particular, after an accurate analysis of philosophical early works, and especially of the paper “Is All Truth Only Eternal or Is It Also True without a Beginning?” (1913), we could demonstrate that logical time in Leśniewski's works is inevitably double. Indeed, on the one hand, the truth of the sentences must be eternal and, on the other hand, these sentences develop in a well-defined time and space element (that is the time and space of their graphic construction). Similarly, this double temporality emerges in the Ontology (1919), a logical calculus of names that presents an axiomatization established on the basis of functor ε, a logical connective inscribed in a specific time and space without any simultaneous temporal determination. This argument gives rise to a whole series of questions: How can we justify the ontological status of this “being” with a timeless connotation, an uncontested and indisputable place of every logical truth inside a developmental perspective in which it is inevitably inscribed? Which are the conditions of possibility of the coexistence of these two temporal determinations? In order to answer these questions we had to set up a detailed study of the nature of this logical time.