  For the Vaibhāṣikas the justification for maintaining the  existence of dharmas in all three temporal dimensions is provided by  their causal theory of cognition: since cognitive awareness cannot  arise in the absence of an objective support, the cognition must be  causally related to the object. The object, therefore, must be real, for  nonexistent objects lack causal efficacy (as we discussed in   §5.1).  