SECTION III.

OF NATURAL SIGNS.

As in artificial signs there is often neither similitude between the sign and the thing signified, nor any connexion that arises necessarily from the nature of the things; so it is also in natural signs. The word gold has no similitude to the substance signified by it; nor is it in its own nature more fit to signify this than any other substance: yet by habit and custom it suggests this and no other. In like manner, a sensation of touch suggests hardness, although it hath neither similitude to hardness, nor, as far as we can perceive, any necessary connexion with it. The difference betwixt these two signs lies only in this, that, in the first, the suggestion is the effect of habit and custom; in the second, it is not the effect of habit, but of the original constitution of our minds.

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It appears evident from what hath been said on the subject of language, that there are natural signs, as well as artificial; and particularly that the thoughts, purposes, and dispositions of the mind have their natural signs in the features of the face, the modulation of the voice, and the motion and attitude of the body that without a natural knowledge of the connexion between these signs, and the things signified by them, language could never have been invented and established among men: and that the fine arts are all founded upon this connexion, which we may call the natural language of mankind. It is now proper to observe, that there are different orders of natural signs, and to point out the different classes into which they may be distinguished, that we may more distinctly conceive the relation between our sensations and the things they suggest, and what we mean by calling sensations signs of external things.

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The first class of natural signs comprehends those whose connexion with the thing signified is established by nature, but discovered only by experience. The whole of genuine philosophy consists in discovering such connexions, and reducing them to general rules. The great lord Verulam had a perfect comprehension of this, when he called it an interpretation of nature. No man ever more distinctly understood, or happily expressed, the nature and foundation of the philosophic art. What is all we know of mechanics, astronomy, and optics, but connexions established by nature, and discovered by experience or observation, and consequences deduced from them? All the knowledge we have in agriculture, gardening, chymistry, and medicine, is built upon the same foundation. And if ever our philosophy concerning the human mind is carried so far as to deserve the name of science, which ought never to be despaired of, it

must be by observing facts, reducing them to general rules, and drawing just conclusions from them. What we commonly call natural causes, might, with more propriety, be called natural signs, and what we call effects, the things signified. The causes have no proper efficiency or causality, as far as we know; and all we can certainly affirm, is, that nature hath established a constant conjunction between them and the things called their effects; and hath given to mankind a disposition to observe those connexions, to confide in their continuance, and to make use of them for the improvement of our knowledge, and increase of our power.

A second class is that wherein the connexion between the sign and the thing signified is not only established by nature, but discovered to us by a natural principle, without reasoning or experience. Of this kind are the natural signs of human thoughts, purposes, and desires, which have been already mentioned as the natural language of mankind. An infant may be put into a fright by an angry countenance, and soothed again by smiles and blandishments. A child that has a good musical. ear may be put to sleep or to dance, may be made merry or sorrowful, by the modulations of musical sounds. The principles of all the fine arts, and of what we call a fine taste, may be resolved into connexions of this kind. A fine taste may be improved by reasoning and experience: but if the first principles of it were not planted in our minds by nature, it could never be acquired. Nay, we have already made it appear, that a great part of this knowledge which we have by nature is lost by the disuse of natural signs, and the substitution of artificial in their place.

A third class of natural signs comprehends those which, though we never before had any notion or conception of the things signified, do suggest it, or conjure it up, as it were, by a natural kind of magic, and at once give us a conception, and create a belief of it. I showed formerly that our sensations suggest to us a sentient being or mind to which they belong: a being which hath a permanent existence, although the sensations are transient and of short duration: a being which is still the same, while its sensations and other operations are varied ten thousand ways: a being which hath the same relation to all that infinite variety of thoughts, purposes, actions, affections, enjoyments, and sufferings, which we are conscious of, or can remember. The conception of a mind is neither an idea of sensation nor of reflection; for it is neither like any of our sensations, nor like any thing we are conscious of. The first conception of it, as well as the belief of it, and of the common relation it bears to all that we are conscious of, or remember, is suggested to every thinking being, we do not know how.

The notion of hardness in bodies, as well as the belief of it,

are got in a similar manner; being by an original principle of our nature annexed to that sensation which we have when we feel a hard body. And so naturally and necessarily does the sensation convey the notion and belief of hardness, that hitherto they have been confounded by the most acute inquirers into the principles of human nature, although they appear, upon accurate reflection, not only to be different things, but as unlike as pain is to the point of a sword.

It may be observed, that as the first class of natural signs I have mentioned, is the foundation of true philosophy, and the second the foundation of the fine arts, or of taste; so the last is the foundation of common sense; a part of human nature which hath never been explained.

I take it for granted, that the notion of hardness, and the belief of it, is first got by means of that particular sensation, which, as far back as we can remember, does invariably suggest it; and that if we had never had such a feeling, we should never have had any notion of hardness. I think it is evident, that we cannot, by reasoning from our sensations, collect the existence of bodies at all, far less any of their qualities. This hath been proved by unanswerable arguments by the bishop of Cloyne, and by the author of the Treatise of Human Nature. It appears as evident, that this connexion between our sensations and the conception and belief of external existences, cannot be produced by habit, experience, education, or any principle of human nature that hath been admitted by philosophers. At the same time, it is a fact, that such sensations are invariably connected with the conception and belief of external existences. Hence, by all rules of just reasoning, we must conclude, that this connexion is the effect of our constitution, and ought to be considered as an original principle of human nature, till we find some more general principle into which it may be resolved.

SECTION IV.

OF HARDNESS, AND OTHER PRIMARY QUALITIES.

FURTHER I observe, that hardness is a quality, of which we have as clear and distinct a conception as of any thing whatsoever. The cohesion of the parts of a body with more or less force is perfectly understood, though its cause is not: we know what it is, as well as how it affects the touch. It is therefore a quality of a quite different order from those secondary qualities we have already taken notice of, whereof we know no more naturally than that they are adapted to raise certain sensations in If hardness were a quality of the same kind, it would be a

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proper inquiry for philosophers what hardness in bodies is? and we should have had various hypotheses about it, as well as about colour and heat. But it is evident that any such hypothesis would be ridiculous. If any man should say, that hardness in bodies is a certain vibration of their parts, or that it is certain effluvia emitted by them which affect our touch in the manner we feel such hypothesis would shock common sense; because we all know, that if the parts of a body adhere strongly, it is hard, although it should neither emit effluvia, nor vibrate. Yet at the same time, no man can say, but that effluvia, or the vibration of the parts of a body, might have affected our touch in the same manner that hardness now does, if it had so pleased the Author of our nature and if either of these hypotheses is applied to explain a secondary quality, such as smell, or taste, or sound, or colour, or heat, there appears no manifest absurdity in the supposition.

The distinction betwixt primary and secondary qualities hath had several revolutions. Democritus and Epicurus, and their followers maintained it. Aristotle and the Peripatetics abolished it. Des Cartes, Malebranche, and Locke, revived it, and were thought to have put it in a very clear light. But bishop Berkeley again discarded this distinction, by such proofs as must be convincing to those that hold the received doctrine of ideas. Yet, after all, there appears to be a real foundation for it in the principles of our nature.

What hath been said of hardness, is so easily applicable, not only to its opposite, softness, but likewise to roughness and smoothness, to figure and motion, that we may be excused from the application, which would only be a repetition of what hath been said. All these, by means of certain corresponding sensations of touch, are presented to the mind as real external qualities; the conception and the belief of them are invariably connected with the corresponding sensations, by an original principle of human naturé. Their sensations have no name in any language; they have not only been overlooked by the vulgar, but by philosophers; or if they have been at all taken notice of, they have been confounded with the external qualities which they suggest.

SECTION V.

OF EXTENSION.

IT is further to be observed, that hardness and softness, roughness and smoothness, figure and motion, do all suppose extension, and cannot be conceived without it; yet I think it must, on the other hand, be allowed, that if we had any thing hard or

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soft, rough or smooth, figured or moved, we should never have had a conception of extension: so that as there is good ground to believe, that the notion of extension could not be prior to that of other primary qualities; so it is certain that it could not be posterior to the notion of any of them, being necessarily implied in them all.

Extension, therefore, seems to be a quality suggested to us, by the very same sensations which suggest the other qualities above mentioned. When I grasp a ball in my hand, I perceive it at once hard, figured, and extended. The feeling is very simple, and hath not the least resemblance to any quality of body. Yet it suggests to us three primary qualities perfectly distinct from one another, as well as from the sensation which indicates them. When I move my hand along the table, the feeling is so simple, that I find it difficult to distinguish it into things of different natures; yet it immediately suggests hardness, smoothness, extension, and motion, things of very different natures, and all of them as distinctly understood as the feeling which suggests them.

We are commonly told by philosophers, that we get the idea of extension by feeling along the extremities of a body, as if there was no manner of difficulty in the matter. I have sought, with great pains I confess, to find out how this idea can be got by feeling, but I have sought in vain. Yet it is one of the clearest and most distinct notions we have; nor is there any thing whatsoever, about which the human understanding can carry on so many long and demonstrative trains of reasoning.

The notion of extension is so familiar to us from infancy, and so constantly obtruded by every thing we see and feel, that we are apt to think it obvious how it comes into the mind; but upon a narrower examination we shall find it utterly inexplicable. It is true we have feelings of touch, which every moment present extension to the mind; but how they come to do so, is the question; for those feelings do no more resemble extension, than they resemble justice or courage; nor can the existence of extended things be inferred from those feelings by any rules of reasoning: so that the feelings we have by touch can neither explain how we get the notion, nor how we come by the belief of extended things.

What hath imposed upon philosophers in this matter, is, that the feelings of touch, which suggest primary qualities, have no names, nor are they ever reflected upon. They pass through the mind instantaneously, and serve only to introduce the notion and belief of external things, which by our constitution are connected with them. They are natural signs, and the mind immediately passes to the thing signified, without making the least reflection upon the sign, or observing that there was any such thing. Hence it hath always been taken for granted, that