Summary: the reality of external objects is refuted by the Yogacara through various arguments, such as cognition apprehending itself, the influence of subconscious impressions on perceptions, and the lack of contact between objects and cognitions in dreams and illusions. The Nyaya critique challenges the Sautrantika realism by questioning the validity of simplistic causal relationships and pointing out inconsistencies in the perceptions of external objects. Ultimately, the debate between realism and idealism centers on the nature of cognition and its relation to external objects, with the Yogacara advocating for the primacy of mind-generated perceptions while the Nyaya emphasizes the existence of external objects as objects of perception.