 Uddyotakara presents an even stronger argument against the skeptics. In his Nyāya-Vārttika he turns Vasubandhu’s own argument against him. Uddyotakara asks: how do we know that the object of a dream experience is non-existent? Vasubandhu accepts that the dreamer does not know that he is dreaming; the knowledge that the object is non-existent occurs only when he awakens and no longer apprehends the object. If non-apprehension of an object in the waking state is required to support the claim that the objects of dream experience do not really exist out there, then apprehension in the waking state must be an indicator of their existence, otherwise there would be no contrast between what is apprehended and what is not (Nyāya-Vārttika, 4.2.33). If there is no such contrast, then Vasubandhu’s argument fails because there is no support for the claim that objects of dream experiences do not exist in the external world. And, if there is such a contrast between apprehension and non-apprehension, then at least some external objects must exist. Clearly, Vasubandhu’s argument for thesis of universal delusion (or idealism) does not succeed completely, nor are the realists totally defeated.