In a short article entitled 'Did Dignaga accept four types of perception? ' published in the Jounal of Indian Philosophy in 1993, Franco propounds the view that Dignaga (ca. 480-540) accepts only three types of perception, namely, sense, mental and yogic perception. As a matter of fact, he was not the first one to propagate this view. Those who agree with him include some eminent scholars in the field of Dignaga and Buddhist epistemological studies, such as Hattori, Nagatomi, Nagatomo, and Schmithausen. The only person that seemed to go against this prevailing view, according to Franco, was Wayman. In his article targeted by Franco, Wayman himself, however, dose not provide any solid evidence that Dignaga actually accepts one more type of perception, i.e., self-cognition(svasamvedana). Therefore, it seems that Franco and others have reached a convincing conclusion on this issue.
