In a recently-published essay on Althusser’s late work which should be read alongside Philosophy of the Encounter, the Italian philosopher Vittorio Morfino isolates and discusses five key concepts of aleatory materialism: the void, the encounter, the fact, the conjuncture and necessity/contingency.

The void represents for Althusser the possibility of action - it is in a sense the space where the encounter may take place. The encounter is a unique event, a contingent coming together of diverse ‘elements’: it may or may not ‘take hold’, ie persist and become a fact. The conjuncture is a term which is familiar from Althusser’s earlier work - now it names the conditions in which encounters take place and (sometimes) take hold. Necessity/contingency is a double-sided concept inspired by Althusser’s obsession with creating a philosophy that is both materialist and anti-teleological. Althusser emphasises that necessity can be grounded in contingency - that a phenomenon which necessarily creates all sorts of effects was nevertheless itself formed contingently.

(from a lengthy and worthwhile article on Althusser over at Reading the Maps)

Why does this sound so familiar? As in: for “conjuncture” read “evental site”…

I meant to post a while back about the significance of the coupling of the “generic” and the aleatory in Badiou. Only when dealing with sets outside of the universe of constructible sets does the Axiom of Choice have any real magic to do, in that it can be used to produce a well-ordering - one choice at a time - of a set to which no discernible principle of ordering can be applied. A generic set has the observable property that one can, via AoC, take an element from it (and discern the remainder, via the axiom of separation, as the set of those elements of the generic set that are not the element one has just obtained); by repeating this procedure one can derive an ordered sequence. The sequence so produced is “aleatory” inasmuch as one cannot find any consistent rule to determine which element should come next; and this I think is what makes the “faithful procedure” local, since if a consistent rule could be found one would instantly obtain a global view of the sequence. To me the whole thing has a sort of coalgebraic flavour…