object to the organ, you may follow its refractions by the lens of the eye, you may detect the picture on the retina, you may explore the connection of the optic nerves with the brain; but you do not by all these discoveries, valuable as they are, alter in the slightest degree the resulting state of consciousness denominated seeing the object. Although they are facts in the physical process absolutely necessary to the result, a knowledge of them does not in the least modify the consequent perception.

Hence it follows that no extent of investigation, no discovery in science, can ever change the character of our acquaintance with external objects. If we could push our insight of nature to the utmost imaginable extreme, if we could ascertain the shape and pursue the movements of every particle of matter in the world around us, we should still have only the same kind of knowledge, although highly exalted in degree, which we have now: we should still be acquainted with the material universe only through our sensitive organs. The telescope and microscope, while they extend the reach of our senses, do not in the faintest degree alter the nature of our perceptions. And further, all the various steps in the physical process through which we become cognisant of any external object, are external objects themselves, and are perceived in the same way as the rest.

Another point which it

may appear almost puerile to insist upon, but which, as will hereafter appear,

it is needful to notice, is that our acts or states of perception cannot produce any effect upon the objects perceived. The mere action of looking at an object does not manifestly affect its qualities; it merely presents an organ for some of those qualities to act upon: nor does the withdrawal of the look make the slightest difference in their nature; it does no more than take away the nervous expanse on which some of them operated.

The simple and proper view is, that in perception, except by the act of directing our organs to external objects, we are passive, and may be described as possessing organs through which, without any other active cooperation on our part, certain conditions of matter produce in us states of consciousness termed the perception of objects or their qualities.

Some of these qualities, it is almost needless to say, are perceived through one organ and its nervous apparatus, some through another.

Colour is a quality of matter perceptible, as far as we know (speaking of terrestrial existences), only by a being provided with an organ called an eye: sound only by a being provided with an organ called an ear.

When a percipient being having such organs, is placed amongst these conditions or qualities of matter, he perceives certain objects; that is, he sees colours and hears sounds: when he is removed from them, the conditions continue to exist, but

the objects of course are unperceived-the act of perception ceases.

In illustration of this subject, let us turn to some well known combination of the visible and the audible, such as the magnificent Falls of Niagara.

Here for ages, before a human eye ever looked upon them, or a human ear ever heard their deafening thunder, the same actions were taking place in the water and the air as take place in the presence of eager crowds of modern visitors. The rays of the sun, whenever they fell on the scene, were refracted by the vapour rising above the torrent ; the air was constantly agitated by the vast mass of water precipitating itself over the rock. But there was no perception of what was going on, of the tranquil iris bending over the abyss, or of the roar of the headlong cataract. It required a being endowed with the special organs called eyes and ears to see the beautiful bow, and to hear the stupendous roar. The moment these organs were brought into contact with the agencies at work, the iris and the roar were perceived.

Some one, nevertheless, may reply that, even according to the representation just given, colour (to speak only of one quality for the sake of simplification) does not exist in the object when no eye looks upon it. Yes, I rejoin, it exists ready to present itself to any visual organ which may be turned towards it. The perception of colour, indeed, would not exist in the supposed case, because

it is a mental act, and the difficulty on your part arises from your meaning by the term colour a perceived instead of a perceptible quality. A perceived quality cannot of course exist without a percipient, but the quality or object is at all times. perceptible, and continues to exist unaltered whether your eye is upon it or not. You surely do not require that an object should look coloured when there is no eye to see it. The only possible thing is that it should appear so whenever there is a spectator to observe it. This is all that can be meant by a coloured body; it is a body that you always perceive to be coloured when you turn your eyes upon it. How it looks when unseen is a question I do not presume to interfere with, not being able to conceive any method by which so self-contradictory an inquiry can be satisfied.

A favourite theory on this particular subject of colour has been that the colour is in the mind ; according to some that it inheres in the mind; and in the language of others, that the mind spreads it over external objects; all which are attempts to explain what does not require or admit of explanation.

The preceding considerations will, I think, enable us to discern where the weakness of this kind of speculation lies.

Let us first examine it as stated by Hobbes.

He maintains "that the subject wherein colour and image are inherent, is not the object or thing

seen that there is nothing without us (really) which we call an image or colour; that the said image or colour is but an apparition to us, of the motion, agitation, or alteration which the object worketh in the brain or spirits, or some internal substance of the head; that as in vision, so also in conceptions that arise from the other senses, the subject of their inherence is not the object but the sentient." He subsequently adds: "whatsoever accidents or qualities our senses make us think there be in the world, they be not there, but are seeming and apparitions only: the things that really are in the world without us, are those motions by which these seemings are caused."

Here it is to be remarked, in the first place, that the image [object] or colour is asserted to be only the appearance to us of the motion worked in the brain.

Supposing such a motion to take place (which is doubtless a very probable inference), yet, as I have already explained, we are not in the least conscious of it, and consequently it cannot be said to appear to us; it may be the cause of the appearance,-i. e., of our seeing the coloured object, but cannot be that which we see, or the appearance itself. The supposed motion in the brain is a physical event, which we infer but do not perceive; the result the perception of the object-is a mental one, or, in other words, it is the particular state of consciousness called seeing.