 Kant’s work inspired this stance on the relation between thinking and being, as we see in Hartmann’s sophisticated interpretation of Kant’s “supreme principle.” Readers will recall Kant’s principle: “the conditions of the possibility of experience in general must at the same time be the conditions of the possibility of the objects of experience” (Kant 1998 [1787], A158/B197). This was Kant’s attempt to formulate a universal basic principle for the relation between thinking and the world. For Kant, this meant that the intersubjectively and objectively valid “forms of intuition” and the “concepts of the understanding,” which science relies on to explain the objects of experience, must be dictated by the mind to the world in its very experience of things. Hartmann argued that this expresses a “restricted identity thesis,” meaning that the principles or conditions of both subject and object are neither completely identical nor completely different. As Hartmann reads it, Kant’s principle is itself entirely “this side” of the distinction between idealism and realism. In other words, it can be interpreted in the direction of placing the conditions of experience inside the subject (Kant’s idealist solution), or both within and beyond the subject in the world (a realist solution). Hartmann claims that Kant’s idealistic interpretation, which makes these conditions internal to the cognizing (transcendental) subject, results from a “dogmatic prejudice.” He believes that a solution that remains faithful to the phenomena of cognition can be proposed that places the principles or conditions of experience not within the subject but within the wider reality of which both subject and object are parts. The at least “partial identity” between subject and object which conditions the possibility of knowledge results from the fact that both subject and object are determined by some shared ontological principles structurally superior to both. In other words, according to Hartmann, in his explanation of valid a priori cognition, Kant relied on a false dichotomy. Either representations are determined by the object, or the object is determined by representations. Hartmann points out that this is not a complete disjunction, and so is false. The third possibility is that both representation and object are determined by a third factor, namely, principles that are valid for both subjects and objects. These principles are what Hartmann calls categories. The partial identity of cognitive and ontological categories, however, must be very carefully delimited. This is the work of categorial analysis, the central task of ontology. Incidentally, many of Hartmann’s responses to Kantian idealism anticipate those of recent “new realists” and “speculative realists” by almost a century (Peterson 2017a).