be identified either with Mind or with Matter. Thus is Materialism included in the same condemnation with Idealism.... See then how far we have travelled from the scholastic theory of occult substrata underlying each group of phenomena. These substrata were but the ghosts of the phenomena themselves; behind the tree or the mountain a sort of phantom tree or mountain, which persists after the body of perception has gone away with the departure of the percipient mind. Clearly this is no scientific interpretation of the facts, but is rather a specimen of naive barbaric thought surviving in metaphysics. The tree or mountain being groups of phenomena, what we assert as persisting independently of the percipient mind is a something which we are unable to condition either as tree or as mountain. "And now we come down to the very bottom of the problem. Since we do postulate Absolute Existence, and do not postulate a particular occult substance underlying each group of phenomena, are we to be understood as implying that there is a single Being of which all phenomena, internal and external to consciousness, are manifestations? Such must seem to be the inevitable conclusion, since we are able to carry on thinking at all only under the relations of Difference and No-difference.... It may seem that, since we cannot attribute to the Absolute Reality any relations of Difference, we must positively ascribe to it No-difference. Or, what is the same thing, in refusing to predicate multiplicity of it, do we not virtually predicate of it unity? We do, simply because we cannot think without so doing."[38]