the impressions, it must have the specific sensuous character which belongs to these. It must be a multitude of sounds, a multitude of tastes, a multitude of smells--these one after the other in endless series. How then can such a series of impressions become such an idea, _i.e._ so grow fainter as to be ‘conjoined’ indifferently ‘with any impressions whatever’? How can he adjust the exact sciences to his theory of space and time? 263. The case then between Hume and the conceptions which the exact sciences presuppose, as we have so far examined it, stands thus. Of the idea of quantity, as such, he gives no account whatever. We are told, indeed, that there are ‘unites which can exist alone,’ _i.e._ can be felt separately, and which are indivisible; but how such unites, being separate impressions, can form a sum or number, or what meaning a unite can have except as one of a number--how again a sum formed of separate unites can be a continuous whole or magnitude--we are not told at all. Of the ideas of space and time we do find an account. They are said to be given in impressions, but, to justify this account of them, each impression has to be taken to be at the same time a consciousness of the manner of its own existence, as determined by relation to other impressions not felt along with it and as interpreted in a way that presupposes the unexplained idea of quantity. With this supposed origin of the ideas the sciences resting on them have to be adjusted. They may take the relations of number and magnitude, time and space, for granted, as ‘qualities of perceptions,’ and no question will be asked as to how the perceptions come to assume qualities confessed to be ‘independent of their own nature.’ It is only when they treat them in a way incompatible not merely with their being feelings--that must always be the case--but with their being relations between felt things, that they are supposed to cross the line which separates experimental knowledge from metaphysical jargon. So long then as space is considered merely as the relation of externality between objects of the ‘outer,’ time as that of succession between objects of the ‘inner,’ sense--in other words, so long as they remain what they are to the earliest self-consciousness and do not become the subject matter of any science of quantity--if we sink the difference between feelings and relations of felt things, and ask no questions about the origin of the distinction between outer and inner sense, they may be taken as data of sensitive experience. It is otherwise when they are treated as quantities, and it is their susceptibility of being so treated that, rightly understood, brings out their true character as the intelligible element in sensitive experience. But Hume contrives at once to treat them as quantities, thus seeming to give the exact sciences their due, and yet to appeal to their supposed origin in sense as evidence of their not having properties which, if they are