there discussed four possible modes of viewing the great problem presented by the existence of sensible objects: Common and Metaphysical Realism, Moderate and Complete Idealism. Let us briefly reconsider these several systems to discover whether any of them affords a satisfactory solution.
Common Realism is excluded by the consideration that it treats the qualities of external objects as existing in those objects and not in the percipient subject. It requires but little reflection to prove that such qualities are modes of consciousness, not modes of absolute being. This defect is surmounted in Metaphysical Realism, which, however, is liable to the fatal objection, that it takes for granted an abstract substance in material things, which substance is like the Unknowable, utterly inconceivable, yet is not the Unknowable, and is incapable of accounting for any of the manifestations belonging to the mental order. So that we should have a superfluous entity brought in to form the substance of matter, of which entity neither our senses, nor our reason, nor our emotions, give us any information. For matter, in the abstract, is not the matter perceived by the senses; nor is it the object of the religious sentiment; nor is its existence capable of any kind of proof save that which consists in establishing the necessity of some kind of Permanent Reality below phenomena. And this Reality is not only the substratum of material, but of all phenomena whatsoever. Moderate Idealism is in no better case. For in denying all true existence except to living creatures it fails utterly to give any rational account of that order of events which is universally and instinctively referred to external causes, nor can it find any possible origin for the living creatures in whose reality it believes. Extreme Idealism recognizes no problem to be dealt with, and can therefore offer no solution.
Each of these systems, however, while false as a whole, contains a partial truth. Extreme Idealism is the outcome of the ordinary, unreflecting Realism; for if the Common Realist be convinced that appearances do not imply existence, and if he believe in no existence but appearances, the ground is cut from under his feet, and he remains standing upon nothing. He knows only phenomena, and the phenomena are mere ideas of his own mind. The truth common to these two extremes is
