 Regarding the appearing object and the apprehended object, a major cause of dissension lies in the model adopted to account for the process of a cognition of an object. Two options are in competition in the external-realist model: (i) direct realism (associated with the Vaibhāṣika model) advocates a direct contact with reality; in this model the object and its cognition exist simultaneously, albeit distinctly; (ii) a causal theory (associated with the Sautrāntika model) according to which an object acts as a cause for the emergence of its cognition but, being momentary, has ceased to exist once this cognition arises.