Even with these revisions in place, it seems to me that Meillassoux mischaracterises the thrust of the Kantian strategy. Kant is not trying to redefine truth or objectivity in intersubjective terms, under the pressure of epistemological constraints introduced by transcendental idealism. Instead, he attempts to vindicate certain a priori concepts — such as the categories of the understanding — as being objectively valid. For example, these concepts include like causality, as a necessary connection between two events. These concepts figure in Kant’s attempt to provide a reformed and legitimate metaphysics, able to justify the concepts to which it appeals. In contrast with empirical concepts, such as bear or atom, we supposedly cannot give a full defence of them by simply looking to the world and seeing whether there is anything which corresponds to them (recall Hume’s scepticism about justifying causality). For Kant, these concepts have a special status: “since they speak of objects through predicates not of intuition and sensibility but of pure a priori thought, they relate to objects universally, that is, apart from all conditions of sensibility.” (B120) Not being based upon experience, they “arouse suspicion.”

If Kant had argued that truth is reducible to universalizable intersubjectivity, then the first Critique would’ve been far less devastating for both traditional metaphysics, as well as skepticism. What Kant is really after with his transcendental philosophy is a critique of introspection by way of introspection.