But, as it seems to me, we now know too much about matter to be materialists. The philosophical difficulties in the way of accepting a materialistic world-system are notorious—at least to philosophers. But I am not speaking of them. I am thinking of the scientific difficulties, those that cannot but suggest themselves when we consider the breach of continuity involved in the appearance of life, and still more obviously of feeling, at particular points in the long procession of material causes and effects. The very essence of the physical order of things is that it creates nothing new. Change is never more than a redistribution of that which never changes. But sensibility belongs to the world of consciousness, not to the world of matter. It is a new creation, of which physical equations can give no account; nay, rather, which falsifies such equations; which requires us to say that, before a certain date in the history of the universe, energy in one shape was converted into precisely the same amount of energy in another shape, and into nothing more; that matter in one position was transferred to another position without increase or diminution: but that, after this date, the transformations of energy and the movements of matter were sometimes accompanied by psychical “epiphenomena” which differ from them in kind, which are incommensurable with them in amount, and which no equations can represent. Babbage, in order to show how occasional “miracles” might “naturally” break the continuity of the longest sequences, devised a machine which produced numbers according to a particular law for an indefinite period, then broke this uniformity by a single exception, and, thereafter, reverted for ever to its original principle of action. But Babbage’s results, however startling, depended wholly on known mathematical and mechanical laws. Their irregularity was only apparent. To Laplace’s calculator, they would have seemed not merely inevitable but obvious. It is quite otherwise with the appearance and disappearance of feeling, thought, will, consciousness in general, within the strictly determinal series of mechanical causes and effects. Here the anomaly is real: the breach of continuity inexplicable by any physical laws and indeed incompatible with them. I am not at this moment concerned either to deny or to assert that at the critical frontier where mind and matter meet, the even course of nature suffers violence. I am not suggesting, for example, that, if a given physiological state were exactly repeated, the psychical state formerly associated with it would not be repeated also. My point is different. It is that in a strictly determined physical system, depending on the laws of matter and energy alone, no room _has_ been found, and no room _can_ be found, for psychical states at all. They are novelties, whose intrusion into the material world cannot be denied, but whose presence and behaviour cannot be explained by the laws which that world obeys.