is a word which is so well understood, that it is difficult for the lexicographer to give any explanation of it. It has been called the first and most simple act of the mind by which it is conscious of its own ideas. This definition, however, is improper, as it confounds perception with consciousness; although the objects of the former faculty are things without us, those of the latter the energies of our own minds. Perception is that power or faculty by which, through the medium of the senses, we have the cognizance of objects distinct and apart from ourselves, and learn that we are but a small part in the system of nature. By what process the senses give us this information, we have endeavoured to show elsewhere, (see Metaphysics, Part I. chap. i.) and we should not again introduce the subject, but to notice a singular opinion of a very able writer, whose work has been given to the public since our article alluded to had issued from the press.

Dr Sayers has endeavoured to prove that no man can perceive two objects, or be conscious of two ideas at the same instant. If this be true, not only our theory of time (see Metaphysics, Part II. chap. vii.) is grossly absurd, but even memory itself seems to be an imaginary faculty. If a man be not conscious of his present existence, at the very instant when he thinks of a past event, or reviews a series of past transactions, it is difficult, to us indeed impossible, to conceive what idea he can have of time, or what he can mean when he says that he remembers a thing. But let us examine the reasoning by which the ingenious author endeavours to establish his opinion.

"If we reflect (says he) upon the surprising velocity with which ideas pass through the mind, and the remarkable rapidity with which the mind turns itself, or is distracted from one object of contemplation to another, this might alone give us some suspicion that we may probably be mistaken in supposing ideas to be synchronously perceived. Other arguments may be adduced to strengthen this suspicion. It will be granted, I believe, that the mind, whether immaterial or the result of organization, has certainly a wholeness or unity belonging to it, and that it is either not composed of parts, or that no one of the parts from which it originates is itself mind: in this case, it is difficult to conceive how two ideas should be impressed upon the mind at the same instant: for this would be supposing that part of the mind could receive one idea, and part another, at the same time; but if the parts do not perceive singly, this is evidently impossible. If, on the other hand, this self-division of the mind does not take place, then if two ideas are nevertheless to be perceived at the same instant, it would seem that those ideas must be so blended with each other, that neither of them could appear distinct. If we examine the manner in which a complex idea is perceived, we shall find very clearly, that the whole of such an idea is never present to the mind at once. In thinking of a centaur, for instance, Perception, can we at the same moment be thinking of the parts of a man and the parts of a horse? Can we not almost detect the gliding of the mind from the one to the other? In contemplating the complex idea of gold, are the ideas of its colour, ductility, hardness, and weight, all present to the mind at the same instant? I think, if we accurately attended to it, we shall find a perceptible time has elapsed before this complex idea has been perfectly formed in our mind; but if all the parts of a complex idea cannot be recalled at the same instant, is it not reasonable to infer that these parts are also singly impressed, and not all originally perceived at the same instant?"

This reasoning is plausible, but perhaps not convincing. Surely we have all been conscious of bodily pain or pleasure with our eyes open, and been offended by disagreeable smells at the very instant that we looked at objects beautifully coloured. That our ideas pass through the mind with great velocity, and that the mind can rapidly turn itself from one subject of contemplation to another, are truths which cannot be controverted; but instead of leading us to suppose that two or more objects cannot be synchronously perceived, or two or more ideas synchronously apprehended, they appear to furnish a complete proof of the reverse of all this. For we beg leave to ask how we come to know that ideas pass with velocity through the mind, if we be not all the while conscious of something that is permanent? If we can contemplate but one idea at once, it is plainly impossible that two or more can be compared together; and therefore we cannot possibly say that any particular train has passed through the mind with a degree of velocity greater or less than that which we usually experience; nay, we cannot say that we have ever experienced a train of ideas at all, or even been conscious of a single idea, besides the immediate object of present apprehension. That the mind is an individual, we most readily grant; but that it should therefore be incapable of having two ideas synchronously excited in it, is a proposition for which the author has brought no evidence. That it is difficult to conceive how this is done; we acknowledge; but not that it is more difficult than to conceive how a single idea is excited in the mind; for of the mode in which mind and matter mutually operate on each other, we can form no conception. We know that objects make an impression on the organs of sense; that this impression is by the nerves communicated to the brain, and that the agitation of the brain excites sensation in the mind; but in what way it excites sensation we know not; and therefore have no reason to suppose that two or more different agitations may not excite two or more synchronous sensations, as well as one agitation excites one sensation. That the agitation given to the brain operates on the mind, is known by experience; but experience gives us no information respecting the mode of that operation. If the mind be, as our author and we suppose, one individual, it cannot, as mind, be either divisible or extended; and therefore it is certain that the operation in question cannot be, in the proper sense of the word, impression. Hence we have no right to infer, if two objects be perceived at once, either that the idea of the one must be impressed on a part of the mind different from that which receives the impression of the other, or that the two impressions must be so blended with each other, that neither of them could appear distinct; for this would be to reason from one mode of operation to another; with which, upon acknowledged principles, it can have nothing in common.

By far the greater part of our ideas are relics of visible sensations; and of every thing which we can actually see at once, we at once contemplate the idea. That we could at once perceive a centaur, if such a being were presented to us, cannot surely be doubted by any one who has ever looked at a man on horseback; and therefore that we can at the same moment contemplate the whole idea of a centaur, is a fact of which consciousness will not permit us to doubt.—If, indeed, we choose to analyze this complex idea into its component parts, it is self evident that the mind must glide from the one to the other, because the very analysis consists in the separation of the parts, of which, if after that process we think of them, we must think in succession: but that we may have at the same instant, either an actual or ideal view of all the parts of the centaur united, is a proposition so evident as to admit of no other proof than an appeal to experience. In contemplating what the author calls the complex idea of gold, it cannot be denied that the ideas of its colour, ductility, hardness, and weight, are never all present to the mind at the same instant: but the reason is obvious. There are not all ideas, in the proper sense of the word, but some of them are ideas, and some notions, acquired by very different processes and very different faculties. Colour is an idea of sensation, immediately suggested through the organ of sight; ductility is a relative notion, acquired by repeated experiments; and gold might be made the object of every sense, without suggesting any such notion. The writer of this article never saw an experiment made on the ductility of gold, and has therefore a very obscure and indistinct notion of that property of the metal; but he is conscious, that he can perceive, at the same instant, the yellow colour and circular figure of a guinea, and have a very distinct, though relative notion, of its hardness.

We conclude, therefore, that the mind is capable of two or more synchronous perceptions, or synchronous ideas; that during every train which passes through it, it is conscious of its own permanent existence; and that if it were limited to the apprehension of but one idea at once, it could have no remembrance of the past, or anticipation of the future, but would appear to itself, could it make any comparison, to pass away like a flash of lightning.