Knowable and sensible things, considered in themselves, are outside the order of being-known or being-sensed.

[3] Sometimes, however, a relation is something real in one of the relata and a mere being of reason in the other. And this happens whenever the two relata do not belong to a single order. For example, sense perception and knowledge are related to things that are sensible and intelligible. But insofar as the latter are things existing in extramental reality, they are outside the order of sensible and intelligible being. And so there is a real relation in the knowledge and sense perception in vir