A History of Plurality: Martial Gueroult's Radical Idealism and the Metaphilosophical Status of the History of Philosophy

The history of philosophy occupies a peculiar methodological position among philosophical disciplines: in order to legitimize its own practice, it must continually redefine its very object, answering, again and again, the fundamental question of what philosophy is. My presentation will offer a meta-analytical reflection on the foundations of the discipline through the theoretical framework of Martial Gueroult (1891–1976). At its center lies the notion of "radical idealism," conceived as a deliberate reversal of the Hegelian model. Where Hegel subsumes the entire historical unfolding of thought under a single, pre-established philosophy, Gueroult insists that the determination of philosophy's essence must conclude historical inquiry rather than precede it. Radical idealism thus begins from the empirical reality of the history of philosophy (the factual existence and plurality of successive doctrines) in order to derive a system from it, preserving the discipline's genuine experiential ground. On this view, the history of philosophy is neither a linear chronicle of errors nor a graveyard of fossilized ideas, but a constellation of autonomous systems. Each philosophical monument is defined by its singularity, its indivisible integrity, its architectural stability, and its extra-temporal validity: these are closed conceptual worlds that are not eroded by time but endure through their own internal coherence. In specifying what philosophy fundamentally is, Gueroult identifies it with an act of thetic judgment: the positing of true reality. Rather than merely representing or intuiting the world, every philosophy sovereignly decrees it, positing a closed Gedankenwelt and affirming its absolute reality, thereby exposing the common reality of ordinary experience as null. It follows that every genuine philosophy is true, and that its relation to other systems resembles the coexistence of distinct works of art: the truth of one monument does not negate that of another. Rather, all share equal value, coexisting within a shared historical space as an infinite constellation of autonomous systems. Ultimately, this presentation aims to reflect on the metaphilosophical status of the history of philosophy. Through a close examination of Gueroult's radical methodology, I will attempt to outline an original approach to philosophical pluralism, one that takes seriously the ontological and axiological claims embedded within every single philosophy.