§ 6. In the present state of philosophical opinion, the proposition that “whatever is real consists of experience,” or again, “of psychical matter of fact,” is in danger not so much of being rejected, as of being accepted in a fundamentally false sense. If we are to avoid the danger of such misunderstanding, we must be careful to insist that our principle does not assert that _mere_ actuality is a complete and sufficient account of the nature of reality. When we say that there is nothing real outside the world of psychical fact, we are not saying that reality is _merely_ psychical fact as such. What we do say is that, however much more it may be, it is at least that. How much more we can say of reality, beyond the bare statement that it is made up of experiences or psychical matters of fact, it is the task of our metaphysical science to determine; at present our problem, though given to us in its general elements, still awaits solution. In particular, we must take care not to fall into the error of so-called “Subjective Idealism.” We must not say that reality consists of “_the states of consciousness of sentient subjects_” or of “_subjects, and their states_.” We must not falsify our data as metaphysicians by starting with the assumption that the psychical facts of which reality is made up are directly experienced as “states” or “modifications” of “subjects” which are their possessors. Such a theory would in fact contradict itself, for the “subject” or “I,” who am by the hypothesis the owner of the “states,” is never itself given as a “state of consciousness.” Hence Hume was perfectly correct when he argued from the principle that nothing exists but states of consciousness, to the conclusion that the thinker or “subject,” not being himself a state of consciousness, is an illusion. Yet, on the other hand, if there is no thinker or subject to “own” the passing states, they are not properly “states” or “modifications” of anything. Apart from this explicit contradiction in the formulation of the theory that all things are “states of consciousness,” we must also object that the theory itself is not a statement of the data of experience, but a hypothesis about their connection. The division of experience into the self or the subject on the one side and its states on the other is not given in our immediate apprehension, but made in the progress of reflection on the contents of apprehension. Sensible things and their properties never appear to us in our direct apprehension of them to be states or modifications of ourselves; that they really are this and nothing more is simply one hypothesis among others which we devise to meet certain difficulties in our thought. Reality comes to us from the first in the guise of pieces of psychical fact; we feel certain, again, that these pieces must somehow form part of a coherent whole or system. We try to understand and account for this systematic character of the real on the supposition