"In affirming that "what is true is the sign of itself and of what is false", Spinoza avoided any problematic which depended on a "criterion of truth ". If you claim to judge the truth of something by some "criterion", you face the problem of the criterion of this criterion -- since it also must be true -- and so on to infinity. Whether the criterion is external (relation of adequacy between mind and thing, in the Aristotelian tradition) or internal (Cartesian self-evidence), in either case the criterion can be rejected: for it only represents a form of Jurisdiction, a Judge to authenticate and guarantee the validity of what is True. And at the same time Spinoza avoids the temptation of talking about the Truth: as a good nominalist (nominalism, as Marx recognized, could then be the antechamber of materialism) Spinoza only talks about what is "true". In fact the idea of Truth and the idea of the Jurisdiction of a Criterion always go together, because the function of the criterion is to identify the Truth of what is true. Once he has set aside the (idealist) temptations of a theory of knowledge, Spinoza then says that "what is true" "identifies itself", not as a Presence but as a Product, in the double sense of the term "product" (result of the work of a process which "discovers" it), as it emerges in its own production. Now this position is not unrelated to the "criterion of practice", a major thesis of Marxist philosophy: for this Marxist "criterion" is not exterior but interior to practice, and since this practice is a process (Lenin insisted on this: practice is not an absolute "criterion" -- only the process is conclusive) the criterion is no form of Jurisdiction; items of knowledge [connaissances ] emerge in the process of their production. There again, by the contrast between them, Spinoza allows us to perceive Hegel's mistake."