positive noumena, if they existed, would be immaterial entities that can only be apprehended by a special, non-sensory faculty: "intellectual intuition" (nicht sinnliche Anschauung). Kant doubts that we have such a faculty, because for him intellectual intuition would mean that thinking of an entity and its being represented would be the same. He argues that we have no way to apprehend positive noumena:

Since, however, such a type of intuition, intellectual intuition, forms no part whatsoever of our faculty of knowledge, it follows that the employment of the categories can never extend further than to the objects of experience. Doubtless, indeed, there are intelligible entities corresponding to the sensible entities; there may also be intelligible entities to which our sensible faculty of intuition has no relation whatsoever; but our concepts of understanding, being mere forms of thought for our sensible intuition, could not in the least apply to them. That, therefore, which we entitle 'noumenon' must be understood as being such only in a negative sense.