 Vasubandhu does not attempt, here, to prove the karmic causality that justifies his soteriological exclusivism. Instead, he moves directly to prove the non-existence of the self. What is real, he says, is known by one of two means: perception or  inference.[17]  Seven things are known directly, by perception. They include the five objects of the senses (visual forms, sounds, smells, tastes, and touchables), mental objects (mental images or ideas), and the mind  itself.[18]  What is not known directly can only be known indirectly, by inference. As an example, Vasubandhu provides an argument that the five sense organs (eye, ear, nose, tongue, skin) can each be inferred from the awareness of their respective sensory objects. But, he says, there is no such inference for the self. Since Vasubandhu believes in universal momentariness (see the section on Momentariness and Continuity), he would reject Descartes’ deduction of “I am,” as an enduring self, from the perception of the momentary mental event, “I think.”