The first hour was devoted to explaining the title, Destructionis destructio, and its two references: Destructio destructionis, the medieval translation of Averroes' Tahafut at-Tahafut , and Traditionis traditio, the title of the collection published in 1972 by Gérard Granel, the first user of the term "deconstruction", coined by J. Derrida in Grammatologie (1967). After a brief evocation of the figure of G. Granel (1930-2000), philosopher, translator and publisher, we traced the genesis of the Foucault-Derrida "debate" from the publication of "Jacques Derrida et la rature de l'origine" by Granel (1967) and " Cogito et histoire de la folie ", the lecture given in 1963 by Derrida at the Collège philosophique created by Jean Wahl in 1946. After presenting Granel's critique of Foucault's "essential indeterminacy of the notion of archaeology, which commands the whole enterprise" since Folie et déraison, we turned to Foucauldi's critique of deconstruction in 1972 in "Réponse à Derrida" and "Mon corps, ce papier, ce feu", focusing on the critique of the "textualization of discursive practices". We then returned to the lecture's subtitle, "Heidegger, Foucault and Medieval Thought", asking whether or not these three sets had anything in common. Starting with the first two, we reread Foucault's "last interview" of May 29, 1984 on two specific points: Foucault's presentation of Heidegger as the "essential philosopher" who made his reading of Nietzsche possible, and the mention of the "tons of notes" taken on Heidegger in 1950-1952. The first task was to take the exact measure of Foucault's "Heideggerian" studies during his formative years, and to analyze the role of his teacher Jean Hyppolite from this point of view. The hour ended with an evocation of Hyppolite's 1971 tribute text, " Nietzsche, la généalogie, l'histoire", in which Foucault contrasts "genealogy" with the Derridean search for origin, followed by Foucault's response to Giulio Preti (1972), in which he reiterates his rejection of "origin" and the "subject" in terms that seem to take the same distance from Heidegger as from Husserl and phenomenology.
The second hour was devoted to the distinction between the "first" and the "second Foucault". After reviewing the lectures at the Collège de France (1970-1984) and L'Histoire de la sexualité (1976-1984) - timetable, changes, order of publication - the focus was on the turning point between 1976 and 1980, the self-interpretation of 1983/1984 ("Usage des plaisirs et techniques de soi" and "Modifications"), the three alleged shifts - from "the progress of knowledge" to "manifestations of power" - and then the "forms and modalities of the relation to the self through which the individual constitutes and recognizes himself as a subject". We then considered the notion of "truth games" and "truth history". We asked whether the Foucauldian project of a history/analysis of "the games of truth and falsehood through which being is historically constituted as experience, i.e. as something that can and must be thought", was a "Heideggerian" idea. After an examination of the 1980 "personal presentation", written under the pseudonym "Maurice Florence" and claiming to be a "history of the regimes of veridiction" and a "critical history of thought", we posed the question of the Foucault-Heidegger relationship in the double light of self-interpretation and "duality". We addressed the distinction between the "first" and "second" Heidegger, starting with the "Letter to Richardson" (April 1962) and the idea of the "Turning Point"(Kehre), supposedly achieved in 1947 with the Letter on Humanism. We then returned to the question of the "essential philosopher", stressing the need to go back to the Heideggerian corpus, its constitution and dissemination: the Heidegger read by Foucault in the 1950s is not the Heidegger of the Gesamtausgabe, the 1980s or, a fortiori, the 2010s. In order to assess the accepted thesis that, apart from the texts devoted to Ludwig Binswanger in the 1950s, there is no trace of Heidegger's influence on Foucault, we have outlined a new research perspective based on the reading "notes" deposited in 2013 in the Fonds Foucault at the Bibliothèque Nationale.
