DIFFERENT SENSATION NOT DIFFERENT PLACE. 101

out of one another, extended. Now, to take the latter alternative first, we have simply to point out that, in the matter of sensations, there are none such. Sensations are but subjective feelings; they possess intension not extension; and Hamilton has no authority to extend them to the latter. Physiologically there may be a certain breadth of surface affected, or, as in the eye, illuminated, and each nervous filament may correspond to a distinct unit of the sensation (light); but, psychologically, that is not so;-psychologically, it is the sensation (light) we know, and not the membrane; and this sensation (light), this subjective feeling, has degree, but not breadth.

Again, sensations out of one another, as different from one another, will give information of difference, but not of distance or separation-of different quality, but not of different place. If in different sensations, we find, not only difference of quality, but difference of place, then, evidently, this latter is something other than themselves-something that has been added to them. This, in fact, is one of Kant's strongest arguments for the original implication and primitive presupposition of space as an independent, à priori, or pure perception.

Without space, then, there is no possibility of a cognition on our part, whether of the first net on experience of a secondary quality, or of the second net (the outer world) on experience of what Hamilton calls a secundo-primary quality-resistance. Space is the indispensable, radical condition; and it is quite incapable of being deduced from any relation-re

ciprocal or other-of sensations. Nay, as we have seen already, the very attempt to derive a knowledge of space and the primary qualities-empirically—is, from the first, suicidal and absurd; and Hamilton's own sense of failure cannot help breaking out ever and anon in his own words. Even in the midst of reasonings about sensations reciprocally out of each other, he admits that space must be presupposed, else they would be reciprocally out of each other, only as different, but not as in different places; and, feeling, perhaps, the whole floor of natural realism thus sinking beneath him, he fairly gives way at last to a burst of ill-humour, as he exclaims:-' It is truly an idle problem to attempt imagining the steps by which we may be supposed to have acquired the notion of extension; when, in fact, we are unable to imagine to ourselves the possibility of that notion not being always in our possession!' It is quite characteristic, too, that, having thus given vent to his temper, and quite unconscious that he has at once supported, and demonstrated ignorance of, the relative doctrine of Kant, he can, in his stubborn mood, wind up:-' We have, therefore, a twofold cognition of space; a, an à priori, native imagination [not perception] of it in general, as a necessary condition of the possibility of thought [not experience]; and b, under that, an à posteriori or adventitious percept of it, &c.' [and thus he betrays unconsciousness that, to Kant, a and b are one and the same!]

In this way, then, it is patent that a physiological theory of the origin of our cognition of extension,

whether placed in the position of the first net or in that of the second, is, from the very nature of the case, futile, and that Hamilton would have been only judicious had he saved himself this whole industry. An industry, indeed, that transfers the qualities of an unperceived and unknown organism to a perceived and known outer world in such wise that we only know what we do not know, while what we do not perceive is all that we do perceive, must be pronounced extravagant and improbable. Nor less objectionable is the violence which is done to consciousness in that it is transferred from the things without to the nervous tissue within, at the same time that its natural authority is claimed for it-in the new position -a claim which, on the part of Hamilton, can only vitiate his single appeal by demolishing the sole standard to which it is addressed, common sense. The interposition, indeed, of the nervous system between the mind within and the world without, which is the one act of Hamilton, must be declared, as it has been handled by him, supervacaneous and idle; not one difficulty affecting the intercourse of mind and matter having in reality been touched by it; while we are left at last with so insecure and insignificant a non-ego that we may legitimately conclude in regard to the general scheme of Hamilton, that it proves what it would disprove, and disproves what it would prove, or that it directly leads, not to presentative realism, but to cosmothetic idealism! Indeed, it is difficult to conceive any theory of perception more glaringly and thoroughly representative than

that of Hamilton: that outer object, whatever it may be, that we suppose ourselves to perceive, is only in name an outer object; it is an unknown substrate, a phenomenon from the first, and we know it, not by what it presents, but by what it represents the qualities, that is, primary and secondary, of our own nervous net, or, even, as in the case of the latter, of our own mental unit. It itself, the outer object, is never perceived at all-it is only supposed; and it is resistance, a state of our own, that thus supposes— that thus infers it. Nor is it for itself that it is inferred, but only for an other-only as locus, that isonly as place of reflections for qualities to which, whether primary or secondary, it itself may in no respect correspond. Any such correspondence as regards the latter class, Hamilton himself would seem to deny; and we cannot doubt now that, had he understood the evidence of Kant, he would have been similarly minded as regards the former. What universe, then, can we possibly conceive more representative? In Kant, the unknown outer substrate may be perceived at least to harmonise with the inner faculty; but we know of no provision in Hamilton for even so much presentationism as this. His primary qualities were at all times but an insignificant barrier against the great sea of relativity that existed for him everywhere else; but now that these are withdrawn, there is but a single expanse-an expanse of representationism-and its originator is Hamilton! *

Hamilton, who would have inner immediate to outer, not only inserts between them the medium of the nerves, but in order still to effect imme

Not only has the theory, however, a very ingenious look, especially at first hand, but it has also an original look; and we become curious to know how it was come by. Now, on this head, we may point out, in the first place, that what is now so commonly known as Berkeley's theory of vision, contains a very general analogy to the view in question. In both, what is held to be originally known by sight is but the lit or coloured ocular membrane; and in both, all that follows is but what has been called 'the art of seeing things that are invisible'—an art in which touch plays the tutor to sight, and teaches it to translate its own visual figure into its (the tutor's) tactual one. Now, Dr. Thomas Brown is generally admitted to have successfully controverted the assumption of visible figure as an original cognition of sight. To say, then, that Hamilton restored what Brown had destroyed, is not imperfectly to name Hamilton's whole action here. It was probably not from this direction, however, that -Hamilton came on his theory;-though it is quite possible that it was at least partly from this direction that he came on his hatred to Brown. His theory once for all formed, that is, he conceivably found, to his astonishment, that Brown-and this is an experi

diation, he is obliged to interpolate no less than eight contrivances more : the eight conditions, namely, -Attention, Quality, Space, Memory, Judgment, &c.,—which he assumes as necessary and indispensable to every act of perception. Such complicated mediacy contrasts oddly with the simple immediacy it would produce. Space is granted as a presupposition at last; but this presupposition, though it nullifies in advance, is not allowed to pretermit, the whole laborious theory. Then memory, which is representative to Hamilton himself, is a necessary element in what remains presentative all the same!