In a well-known account of the role of transcendental imagination in Kant's philosophy, Martin Heidegger practically accused Kant of intellectual cowardice. Heidegger argued that Kant's refusal in the second edition of the Critique of Pure Reason to grant that the imagination was a fundamental faculty was a result of Kant's having originally identified the transcendental imagination with the “common root” of sensibility and understanding, and of his subsequently being unwilling to grant such basic status to a faculty whose obscure nature frightened him: “He saw the unknown,” Heidegger says, and “he had to draw back.”

In what has become a classic critique of Heidegger's Kant interpretation, Dieter Henrich's “Die Einheit der Subjektivität” (“On the Unity of Subjectivity”) takes up his challenge to the integrity of the Kantian enterprise and defends Kant on the grounds that his refusal to explore the common root of both sensibility and understanding really has nothing to do with Kant's attitude toward the imagination, but rather represents his adoption of the view, already promulgated against Christian Wolff by Christian August Crusius, that subjectivity cannot be traced to a single basic faculty or principle. Far from suggesting the need to identify any common root of human subjectivity, Henrich argues, Kant denies outright the possibility of ever knowing such a basic power and is agnostic about the existence of such a power even apart from the conditions of human knowledge.