The various engagements with the history of philosophy that can be found throughout Alain Badiou's work present not just incisive and fascinating encounters motivated by his own philosophical concerns, but also figure as cases in a serial and topical approach to Western thought. It is possible to envision, for example, a history of the infinite in the style of Badiou in which the treatment of Hegel in Being and Event is an iconic instance. Likewise, one might speculate on a history of fidelity where Pascal and Beckett are joined in a rigorous fashion. Taking this approach, Badiou's œuvre would be traversed by a number of virtual series, manifest in only a few particular cases.

Such a view allows us to appreciate in a summary fashion the proximity of Spinoza to Badiou's work, since the latter finds in Spinoza's metaphysics evidence, licit or otherwise, of almost all of his main ontological concepts: the mathematical access to being, the void, the subject and the generic are all instanced in the pages of the author of the magisterial Ethics.

In fact, what Badiou presents in his main readings of Spinoza is a sketch of the work of an obscure precursor. In his own way, Badiou takes up the famous Hegelian claim according to which “to be a follower of Spinoza is the essential commencement of all philosophy” (Hegel 1974: 253).

The Spinoza who is a precursor to Badiou's own project is not the Spinoza of Althusser, Negri or Deleuze; nor indeed is it even Spinoza's own Spinoza. In Being and Event and Badiou’s Court traité d’ontologie transitoire, we find the sketch of an “implicit, paradoxical Spinozism” (TW 93), a hidden Spinozism, not without its flaws, which invokes a network of conceptual connections in tension with what lies on the surface of Spinoza’s metaphysics.