which, to general observers, seem of a very opposite kind. As the want of musical ear implies no general defect of mere quickness of hearing, this visual defect, in like manner, is to be found in persons, who are yet capable of distinguishing, with perfect accuracy, the form, and the greater or less brilliancy of the coloured object;--and I may remark too, in confirmation of the opinion, that the want of musical ear depends on causes not _mental_ but _organic_; that, in this analogous case, some attempts, not absolutely unsuccessful, have been made, to explain the apparent confusion of colours, by certain peculiarities of the external organ of sight. Though the one case, however, were to throw no light upon the other, it is still gratifying to philosophers, to have a case at all analogous, to which, when they are weary of considering what has baffled all their endeavours to explain it, they may have the comfort of turning away their attention, without the mortification of seeming absolutely to fly from the subject. Such is the strange constitution of our nature, that merely to have another difficulty presented to us, though it may yet be absolutely unsurmountable in itself,--if only it have some slight resemblance to a former difficulty,--seems to us almost as if we had succeeded in explaining the first;--and each difficulty, by a very convenient transposition, which our pride knows well how to make, supplies, according as we may have been considering the one rather than the other, the place of explanation to that which is afterwards to explain it, no less clearly, in its turn.