With the act of knowing stripped of its technique and left a bare, unique, indescribable act or relation, the foundations for epistemological and metaphysical logic were laid. That Greek logic escaped the ravages of epistemology was due to the saving materialism in its metaphysical conception of mind and to the steadfastness of the aristocratic régime. But when medieval theology and Cartesian metaphysics had destroyed the last remnant of metaphysical connection between the knowing mind and nature, and when revolutions had torn the individual from his social moorings, the stage for epistemological logic was fully set. I do not mean to identify the epistemological situation with the Cartesian disjunction. That disjunction was but the metaphysical expression of the one which constitutes the real foundation of epistemology--the disjunction, namely, between the act of knowing and other acts.
From this point logic has followed one of two general courses. It has sought continuity by attempting to reduce non-logical things and operations to terms of logical operations, i.e., to sensations or universals or both; or it has attempted to exclude entirely the act of knowing from logic and to transfer logical distinctions and operations, and even the attributes of truth and error to objects which, significantly enough, are still composed of these same hypostatized logical processes. The first course results in an epistemological logic of some form of the idealistic tradition, rationalism, sensationalism, or transcendentalism, depending upon whether universals, or sensations, or a combination of both, is made fundamental in the constitution of the object. The second course yields an epistemological logic of the realistic type,--again, sensational or rationalistic (mathematical), or a combination of the two--a sort of realistic transcendentalism. Each type has essentially the same difficulties with the processes of inference, with the problem of change, with truth and error, and, on the ethical side, with good and evil.
With the processes of knowing converted into objects, and with the act of knowing reduced to a unique and external relation between the despoiled knower and the objects made from its own hypostatized processes, all knowing becomes in the end immediate. All attempts at an inference that is anything more than an elaborated and often confused restatement of non-logical operations break down. The associational inference of empiricism, the subsumptive inference of rationalism, the transcendental inference of objective idealism, the analytical inference of neo-realism--all alike face the dilemma of an inference that is trifling or miraculous, tautologous or false. Where the knower and its object are so constituted that the only relation in which the latter can stand to the former is that of presence or absence, and if to be present is to be known, how, as Plato asked, can there be any false knowing?