The critique of idealism has long centered on its failure to recognize the primacy of practice—that is, the materialist critique. This paper discusses a non-materialist critique of idealism, one that proceeds solely from the internal logic of idealism itself, without invoking the primacy of practice. This critique operates at the level of transcendental logic, and its core method is reductio ad absurdum: it confirms the existence of an unknowable term that can affect "knowable" terms, and thereby demonstrates that reasoning based solely on "knowable" terms is philosophically illegitimate. After carrying out this critique, the method is abstracted to reveal its universal applicability—not only to idealism, but to all current ontologies. All existing systems of thought harbor an illegitimate intermediate state in which they tolerate the non-omniscient while claiming partial knowledge, a state exposed by this reductio. Consequently, all philosophy must arrive at a more radical ontological posture—agnosticism. Because this agnosticism, derived through ontological reductio, differs from traditional agnosticism, it is termed Neo-Agnosticism. Finally, since critique requires an anchor point of "known correctness," it is shown that Neo-Agnosticism is statically and logically necessarily connected to an Omniscient Drive.