In the Critique of Pure Reason, as Daniel W. Smith explains, the form given to the phenomenal through reflection of the transcendental is what Kant calls the "object = x." This is an empty form that only receives qualitative specifications when related to a multiplicity of phenomenal qualia held together through mental operations. White, thin, and sheet-like bark, dark-black knots, and a thin trunk, for example, are synthesized together mentally to form the object known as a birch tree. Moreover, Kant claims it is such a synthesis that allows the various qualitative impressions had of the birch tree, the sun, one's own hand, and more to be shared between the various faculties. It is because of this synthesis that the same qualia present themselves when, for example, I imagine a birch tree as when I conceptualize one. Pushing Kant's claim further, it might be posited that this synthesis is also what allows each of our various senses to present the same object to us such that when I put my hand to the white sheet-like bark of the tree, the feel of the bark indicates it is a birch tree I am touching, just as the visual appearance of its knots and leaves likewise indicates.
However, the object-form is not itself a transcendental form but rather an analogue of such a form. What of the transcendental human subject has the capacity to produce an analogue of itself that conditions a shared sensory world? The cogito. The cogito for Kant is a unity prior conditionally to all empirical experience. It is the "I think" which gives to the human being a subjecthood by which it can then reach out to the world and make it one's own. Nonetheless, the cogito is neither individual nor personal. Rather, it is the universal form of reason in general. Thus, as an analogue of the cogito, the object-form renders a shared, sensory world not only for one's own senses and faculties but also for one person and another.
