It seems to me that, since 1956, what has happened in H[ungary], Fr[ance] and Belgium has rung the bell on the post-Leninist conception of the workers' movement, with all of its problematics, including progressive anti-St[alinist] "fellow travelers" and Trotskyism.
It is the merit of S[ocialisme] ou B[arbarie] to have developed a profound critique of the bureaucracy. And to have maintained a militant tradition that [Edgar] Morin has sold off to Editions du Seuil and other p[ublishers].
I am surprised that V. is surprised that I am in touch with [S. ou B.] -- Am I in touch with V.? (...) I think that he is a Trotskyist, orthodox (plus careerist).
As for [S. ou B.], I was extremely hostile (and especially during the events of May 58) to the Lefortist tendency. When it split off [from S. ou B.], I wrote to you that this was a very fortunate confirmation. Later on, I met the c[omrades] of this group.
The text "P[reliminaries]," written by C[anjuers] and I (C[anjuers] wrote at least two-thirds of it), expresses quite well, I think, the point of contact between the S[ituationist] I[nternational] and [S. ou B.] (although it isn't strongly approved of by all the sit[uationist]s or others).
To the extent that I cannot conceive that the SI is outside of the political rev[olutionary] m[ovement] (and that the peril of artists' lamentable arrive-ism always re-creates itself by the nature of our activity, and despite the artificial necessity of the SI's discipline); and to the extent that one can't always remain pure, isolated intellectuals, critiquing or having illusions concerning parties judged from the outside; I believe that it is necessary to participate in a re-grouping of revolutionaries, within and outside of B[elgium], on the basis of a critique without illusions, and so an accord can perhaps be realized on fundamental perspectives.
I believe that this accord can be reached on the platform constituted on the initiative of S. [ou B.] and I will try to bring to it the entirety of the sit[uationist] m[ovement].Cordially yours,
 Summary of a letter to Andre Frankin.
 Henri Vaume.
 Claude Lefort, an existentialist at first, an ex-Trotskyist, the co-founder of S. ou B. (under the pseudonym of Cl[aude] Montal), which he left in 1958 to form Information et Correspondence Ouvriere (ICO) before joining Arguments on the French intellectual scene.
(Published in Guy Debord, Correspondance, Volume 2, 1960-1964. Footnotes by Alice Debord. Translated from the French by NOT BORED! April 2005.)