and the figure, if very luminous so far as the general doctrine is concerned, needs only to be looked at to show, on the question of inner rationale, quite as unsatisfactory as any that might be borrowed from any other sense. The mind, for example, Hamilton would seem to think, though already pervading the membrane of the eye, is quite blind to this membrane till this membrane is lit. When lit, however, the mind, instantly confessing this membrane to be itself, experiences the sensation (colour, &c.); but, as instantly denying this membrane to be itself, it experiences the perception of an extended and divided non-ego. But do not the difficulties remain thus-of how the light exhibits, how the attention is excited, and how the one or the other should be at all necessary? It is simple information that we cannot see in the dark; but what is the meaning of the mind requiring light to see its net by?—what power can light have added to such an energy as the mind there? Nay, one would think that the mind, occupying the same position in both cases, would be less likely to attend to its net when filled and occupied (with light), than when empty and disengaged. Hamilton only doubles the apparatus. As it is to common belief, we have an eye whereby to see things; but as it is to Hamilton, we have an eye whereby to see the eye. Or Hamilton actually postulates an eye behind the eye-not only an eye of the body, but an eye of the mind; excess of light too, it would seem, being not more dazzling and perplexing to the one, than it is dazzling and perplexing to the other.

Though it is certainly the coloured or lighted ocular membrane that dominates Hamilton, he as certainly, so far as words go, attributes a like function to the other organs of sense. 'All the senses,' he says (Reid's Works, p. 864), 'simply or in combination, afford conditions for the perception of the primary qualities.' Let us for a moment, then, consider the other senses, and see if it be with them, as the illustration would, at least to a certain extent, appear to make it with sight. How is it with smell? On sensation of an odour, does the mind wake up to peruse its Schneiderian membrane? Or taste? On sensation of sapidity, does the mind re-act on, or is it reflected to, the amount of the palate affected by the sapid particles, and as divided and figured by their varying sapidity? Or hearing? On sensation of sound, does the mind, by instant rebound, stand at once by the wall of its own tympanum, objectively cognising the same? Obviously, there is no evidence for any assertion of the affirmative in either of these cases! In touch, again, is it to the skin, and the amount of skin covered, that the sensation proper of smoothness, or of roughness, wetness, dryness, warmness, coldness, directs the mind? Is it not proved by Hamilton himself that touch is a very bungler at guessing the size of the impressing body-a very bungler at extension? Then is not sight too, according to the same authority, but a form of touch? Do we know aught but 'the rays and the living organ in reciprocity?' The rays touch, then, and we have the subjective feeling light; but why should the mind revert

H

to the organ on hint of this sort of touch, rather than on that of any other touch, and in any other organ? Is not the whole fancy of the mind seeing its eye because it is lit-is not the whole metaphor of light but a will-of-the-wisp to the self-complacent Hamilton?

same.

So far, then, as the sensation proper is the condition of the perception proper, we cannot say that Hamilton has, in any way, assisted us beyond the fact: we see neither the necessity nor the modus operandi of the Hamilton, indeed, says as much as this himself, for the sensation is to him nexus and it is not nexus, it is necessary and it is not necessary, and evidently at last he has simply blindly settled himself into the analogy of light. Why any such stimulus is,-how it acts,-what it does,-Hamilton, taking up his position in the nervous system, is even worse off for an answer here than common sense, which, unlike its professing votary, has really its seat on the ground. It is easy, in the straits of such questions, to bawl out OT, and threaten us with a charge of imbecility at the hands of Aristotle; but, in the end, is there a single difficulty removed? Can it, indeed, be said that any one single difficulty-whether physiological or psychological—as regards brain, and nerves, and light, and images, and vibrations, and tympana, and labyrinths and what not, has received solution at the hands of Hamilton? The position in the nervous system is, in effect, not only gratuitous but idle; and it is very characteristic of Hamilton that he should return in his metaphysical lectures to his dogged or, and wind up, though weakly enough, with such passages as:

'But whether the senses be instruments, whether they be media, or whether they be only particular outlets to the mind incarcerated in the body,-on all this we can only theorise and conjecture.'

Nor is Hamilton one whit luckier in the step to his second net than in that to his first. This step is resistance-voluntary locomotion resisted; and from what we know now, it will not be difficult to perceive that the transition thence to a world without is сараble of being met by the same principles which interposed beween the sensation proper and the perception proper. Resistance, that is, is but a subjective feeling, and how there should be any hint in it of an external object, constitutes the difficulty. Any mental experience, indeed, feeling or other, cannot be referred out, till there be an out known. Nor is it different with locomotion: this, too, would be simply a feeling, more or less intense, and would give no knowledge of movement till ideas of space and an external universe had been already formed; but for the formation of these ideas we find no competent provision supplied by Hamilton.

Hamilton, indeed, asserts direct perception of extension, and extension implies space; but as we have seen, he brings forward for himself no more than assertion; and we are compelled to indicate and demand the missing element of proof. The void between subjective sensation and objective perception he leaves unmediated; and we refuse to participate in the satisfaction he demands for his own mere spring. There are certainly times, however, when the simple

recoil from intension to extension seems insufficient to Hamilton himself-times when, as it appears, he would really mediate between the intensive sensation of the membrane on the one side, and its extensive perception on the other. We have such deliverances as these, for example:-'Sensations out of each other, contrasted, limited, and variously arranged;' 'sensations recognised as plural, and reciprocally external;' 'sensations relatively localised;' 'all sensations, whatsoever, of which we are conscious, as one out of another, eo ipso, afford us the condition of immediately and necessarily apprehending extension.' Now, to judge from such expressions as these, there is more in the thought of Hamilton than that it is simply fact, that the sensation is the condition of the perception: he evidently contemplates something of reason as well. In other words, it is in the peculiar reciprocity of the sensations that he sees the prototype of extension. With this, too, his physiological ideas cohere: he would regard the ultimate fibrils as the ultimate units of sensation;' and he unequivocally attributes to the smaller size of the papillæ and fibrils of the optic nerve the greater power we possess, in the eye, of discriminating one sensation as out of another, and, consequently, of apprehending extension.' The theory that seems involved or desiderated, however, admits of a very simple refutation. The phrase, 'sensations one out of another,' can mean only one or other of two things: either sensations one out of another as different from one another; or sensations that, as such, have parts-that are, in their own nature, plural,