form of intellectual life, has first of all to retract itself into the bare abstract consciousness, or mere self, on which the masses of reality stream, to fill its vacant rooms and empty forms up with ideas. So too the person--that close concretion or coalescence of mind with material--that identification of self with its 'clothes,' its property and all it can vulgarly be said to _own,_ is only an aspect of truth which tends to be over-estimated when it is reflected upon, and must notwithstanding be over-ridden and merged. Withdrawing itself from its clothing of earth and water, and even perhaps from its inner mansion of flesh and bone, personality floats in the free air as the impersonal personality of conscience,--the ethereal realm where pure practical reason rules. In that ether where morals reign absolutely is the home of the categorical imperative, of the Stoical law of duty, of the conscience which, here at least, has might as it has right. It too, like its parallel, consciousness, in the inner mental life, has, or seems to have, all its fulfilment from without. As even Kant admits, it is itself a vacant form; yet a form of such influence as to impress on whatever comes within its range an obligation to be universal and to be uniform. Here too, as in the parallel stage, it was of inestimable importance that mind should, in the socio-ethical sphere, see itself supreme in its innermost dignity and personality,--the personality which lies within,--even though that supremacy were at first no better than as a law, a form, a category, recognised as authoritative and imperative. For conscience, like the field of consciousness, is after all only a quasi-passive self--a remarkable property or endowment, a sort of innate principle or idea by which the mind was seen to be distinguished in a unique way from all things else. To realise once for all the fact that consciousness and conscience form an absolute tribunal from which there can be no appeal: that the 'synthetic unity of apperception' in the theoretical, and the 'autonomy of the rational will' in the practical sphere, are the ultimate and final _a priori_: this is a great thing to do,--even though it only expands and defines the Cartesian principle of clear and distinct ideas, and will remain as Kant's title of honour in the history of philosophy. He thus fenced off or consecrated the sanctuary of the mental and moral life.