compounded of both. Thus, in a globe or cylinder, whose opposite sides are quite unlike in colour, if you turn it slowly, the colours are perfectly distinguishable and their dissimilitude is manifest; but if it is turned fast, they lose their distinction, and seem to be of one and the same colour.

No succession can be more quick than that of tangible qualities to the sensations with which nature has associated them; but when one has once acquired the art of making them separate and distinct objects of thought, he will then clearly perceive that the maxim of Bishop Berkeley, above-mentioned, is self-evident; and that the features of the face are not more unlike to a passion of the mind which they indicate, than the sensations of touch are to the primary qualities of body.

But let us observe what use the Bishop makes of this important discovery. Why, he concludes, that we can have no conception of an inanimate substance, such as matter is conceived to be, or of any of its qualities; and that there is the strongest ground to believe that there is no existence in nature but minds, sensations, and ideas; if there is any other kind of existence, it must be what we neither have nor can have any conception of. But how does this follow? Why, thus: We can have no conception of anything but what resembles some sensation or idea in our minds; but the sensations and ideas in our minds can resemble nothing but the sensations and ideas in other minds; therefore, the conclusion is evident. This argument, we see, leans upon two propositions. The last of them the ingenious author hath, indeed, made evident to all that understand his reasoning, and can attend to their own sensations: but the first proposition he never attempts to prove; it is taken from the doctrine of ideas, which hath been so universally received by philosophers, that it was thought to need no proof.

We may here again observe, that this acute writer ar

gues from a hypothesis against fact, and against the common sense of mankind. That we can have no conception of anything, unless there is some impression, sensation, or idea, in our minds which resembles it, is indeed an opinion which hath been very generally received among philosophers; but it is neither self-evident, nor hath it been clearly proved; and therefore it hath been more reasonable to call in question this doctrine of philosophers, than to discard the material world, and by that means expose philosophy to the ridicule of all men who will not offer up common sense as a sacrifice to metaphysics.

We ought, however, to do this justice both to the Bishop of Cloyne and to the author of the "Treatise of Human Nature," to acknowledge, that their conclusions are justly drawn from the doctrine of ideas, which has been so universally received. On the other hand, from the character of Bishop Berkeley, and of his predecessors, Des Cartes, Locke, and Malebranche, we may venture to say, that, if they had seen all the consequences of this doctrine, as clearly as the author before mentioned did, they would have suspected it vehemently, and examined it more carefully than they appear to have done.

The theory of ideas, like the Trojan horse, had a specious appearance both of innocence and beauty; but if those philosophers had known that it carried in its belly death and destruction to all science and common sense, they would not have broken down their walls to give it admittance.

That we have clear and distinct conceptions of extension, figure, motion, and other attributes of body, which are neither sensations, nor like any sensation, is a fact of which we may be as certain as that we have sensations. And that all mankind have a fixed belief of an external material world-a belief which is neither got by reasoning nor education, and a belief which we cannot shake off, even when we seem to have strong arguments against

it and no shadow of argument for it-is likewise a fact, for which we have all the evidence that the nature of the

thing admits. These facts are phænomena of human nature, from which we may justly argue against any hypothesis, however generally received. But to argue from a hypothesis against facts, is contrary to the rules of true philosophy.

CHAPTER VI.

OF SEEING.

Section I.

THE EXCELLENCE AND DIGNITY OF THIS FACULTY.

THE advances made in the knowledge of optics in the last age and in the present, and chiefly the discoveries of Sir Isaac Newton, do honour, not to philosophy only, but to human nature. Such discoveries ought for ever to put to shame the ignoble attempts of our modern sceptics to depreciate the human understanding, and to dispirit men in the search of truth, by representing the human faculties as fit for nothing but to lead us into absurdities and contradictions.

Of the faculties called the five senses, sight is without doubt the noblest. The rays of light, which minister to this sense, and of which, without it, we could never have had the least conception, are the most wonderful and astonishing part of the inanimate creation. We must be satisfied of this, if we consider their extreme minuteness; their inconceivable velocity; the regular variety of colours which they exhibit; the invariable laws according to which they are acted upon by other bodies, in their reflections, inflections, and refractions, without the least change of their original properties; and the facility with which they pervade bodies of great density and of the closest texture, without resistance, without crowding or disturbing one another, without giving the least sensible impulse to the lightest bodies.

The structure of the eye, and of all its appurtenances, the admirable contrivances of nature for performing all

its various external and internal motions, and the variety in the eyes of different animals, suited to their several natures and ways of life, clearly demonstrate this organ to be a masterpiece of Nature's work. And he must be very ignorant of what hath been discovered about it, or have a very strange cast of understanding, who can seriously doubt whether or not the rays of light and the eye were made for one another, with consummate wisdom, and perfect skill in optics.

If we shall suppose an order of beings, endued with every human faculty but that of sight, how incredible would it appear to such beings, accustomed only to the slow informations of touch, that, by the addition of an organ consisting of a ball and socket of an inch diameter, they might be enabled, in an instant of time, without changing their place to perceive the disposition of a whole army or the order of a battle, the figure of a magnificent palace or all the variety of a landscape! If a man were by feeling to find out the figure of the peak of Teneriffe, or even of St. Peter's Church at Rome, it would be the work of a lifetime.

It would appear still more incredible to such beings as we have supposed, if they were informed of the discoveries which may be made by this little organ in things far beyond the reach of any other sense that by means of it we can find our way in the pathless ocean; that we can traverse the globe of the earth, determine its figure and dimensions, and delineate every region of it; yea, that we can measure the planetary orbs, and make discoveries in the sphere of the fixed stars.

Would it not appear still more astonishing to such beings, if they should be farther informed, that, by means of this same organ, we can perceive the tempers and dispositions, the passions and affections, of our fellowcreatures, even when they want most to conceal them? that, when the tongue is taught most artfully to lie and dissemble, the hypocrisy should appear in the counte