that the inappropriate formulation of the question would not continue to stand.
Along with Dasein as Being-in-the-world, entities within-the-world have in each case already been disclosed. This existential-ontological assertion seems to accord with the thesis of realism that the external world is Really present-at-hand. In so far as this existential assertion does not deny that entities within-the-world are present-at-hand, it agrees—doxographically, as it were—with the thesis of realism in its results. But it differs in principle from every kind of realism; for realism holds that the Reality of the 'world' not only needs to be proved but also is capable of proof. In the existential assertion both of these positions are directly negated. But what distinguishes this assertion from realism altogether, is the fact that in realism there is a lack of ontological understanding. Indeed realism tries to explain Reality ontically by Real connections of interaction between things that are Real.
As compared with realism, idealism, no matter how contrary and untenable it may be in its results, has an advantage in principle, provided that it does not misunderstand itself as 'psychological' idealism. If idealism emphasizes that Being and Reality are only 'in the consciousness', this expresses an understanding of the fact that Being cannot be explained through entities. But as long as idealism fails to clarify what this very understanding of Being means ontologically, or how this understanding is possible, or that it belongs to Dasein's state of Being, the Interpretation of Reality which idealism constructs is an empty one. Yet the fact that Being cannot be explained through entities and that Reality is possible only in the understanding of Being, does not absolve us from inquiring into the Being of consciousness, of the res cogitans itself. If the idealist thesis is to be followed consistently, the ontological analysis of consciousness itself is prescribed as an inevitable prior task. Only because Being is 'in the consciousness'-that is to say, only because it is understandable in Dasein—can Dasein also understand and conceptualize such characteristics of Being as independence, the 'in-itself', and Reality in general. Only because of this are 'independent' entities, as encountered within-the-world,  accessible to circumspection.
If what the term "idealism" says, amounts to the understanding that Being can never be explained by entities but is already that which is 'transcendental' for every entity, then idealism affords the only correct possibility for a philosophical problematic. If so, Aristotle was no less an idealist than Kant. But if "idealism" signifies tracing back every entity to a subject or consciousness whose sole distinguishing features are that it remains indefinite in its Being and is best characterized negatively as