bringing us our other ideas and that the body, being a very complicated machine, as well in the grosser as the finer of its organs, they delight or disturb us in various degrees according as in the variety of their play they approach nearer or remove further from the springs of satisfaction or uneasiness. For as the difference of our ideas depends probably upon the form, or magnitude, or motion, or force of the organs exhibiting them, one cannot suppose the same organ by the variations of its play affecting us either with pleasure or pain without producing an alteration in our ideas. Now what those springs are, where they lie, or by what kind of motion they operate upon us either way, I shall not attempt to describe: nor is it necessary we should know so much; for if we can learn what will give us pleasure or pain, and how to procure the one and avoid the other, we ought to rest fully contented, without knowing the manner in which they produce their effect. And in order to attain so much knowledge as we want, I shall endeavor to examine how our ideas form into compounds, and how satisfaction becomes united to them, or is transferred from one to another.

CHAP. VII.

SENSATION.

SENSATION, as we learn from Mr. Locke, and may find by our own observation, is the first inlet and grand source of knowledge, supplying us with all our ideas of sensible qualities; which, together with other ideas arising from them, after their entrance into the mind, complete our stores of knowledge and materials of

reason..

Sensations come to us from external objects striking upon our senses. When 1 say external, I mean with respect to the mind; for many of them lie within the body, and for the most part reach us by our sense of feeling. Hunger and thirst, weariness, drowsiness, the pain of diseases, repletion after a good meal, the pleasure of exercise and of a good flow of spirits, are all of this kind. But sometimes we receive sensations by our other senses too, coming from no object without us: as in the visions and noises frequent in high fevers; the nauseous tastes accompanying other distempers, and the noisome smell remaining many days with some persons after catching an infection of the small-pox. For whatever in our composition affects our senses in the same manner as

external objects used to do, excites a sensation of the same kind in the mind.

I shall not go about to describe what are to be understood by external objects, for any man may know them better by his own common sense than by any explanation of mine: but I think it worth while to observe that they are not always either the original or immediate causes giving birth to our sensations. When we look upon a picture, the sun or candle shining upon it primarily, and the rays reflected from it and image penciled upon our retina subsequently, produce the idea in our mind; yet we never talk of seeing them, but the picture, which we account the sole object of our vision. So when Miss Curteous entertains you with a lesson upon her harpsichord, both she and the instrument are causes operating to your delight, for you thank her for the favor, and may speak indifferently of hearing the one or the other: but when you consider what is the object of your hearing, you will not call it either the lady or the harpsichord, but the music.

2. It is remarkable that although both visible and sonorous bodies act equally by mediums, one of light and the other of air, vibrating upon our organs, yet in the former case we reckon the body the object, but in the latter the sound of the air: I suppose because we can more readily and frequently distinguish the place, figure, and other qualities, of bodies we see than of those affecting our other senses. We have smells in our noses, but cannot tell what occasioned them; tastes remain in our mouths after spitting out the nauseous thing that offended us: we may feel warmth without knowing from whence it proceeds; and the blow of a stick, after the stick itself has been thrown into the fire and consumed. And that this distinction of bodies denominates them objects of vision, appears further, because some, having in a course of experiments been shown a calf's eye whereon they see the miniature of a landscape lying before it delineated, very learnedly insist that the image penciled on the backside of our eye, and not the body therein represented, is the object we behold. But unless like Aristotle they hold the mind to be existing in every part of our frame, they must allow that neither is this image the immediate object of our discernment, but some motion or configuration of the optic nerves, propagated from thence to the sensoTherefore it is the safest way to take that for the object which men generally esteem to be such: for should we run into a nice investigation of the causes successively operating to vision, we shall never be able to settle whether the object of our lucubrations be the candle, or the light flowing thence, or the letters of our book, or the light reflected from thence, or the print of them

ry.

upon our eye, or the motion of our nerves. If we once depart from the common construction of language, and will not agree with others, that we see the lines we read, we may as well insist that we see the candle, or the optic nerves, as the image in our retina.

But with regard to the sense of hearing there is no such difficulty started, because you cannot, by dissecting a calf's ear, exhibit anything therein to your scholars similar to the lowings of a cow which the calf heard when alive. Wherefore learned and simple agree in calling sound the object of hearing: nevertheless, every one knows that it must proceed from the cry of some animal, play of some instrument, collision, or other action of some body making the sound. When imagination works without anything external to strike upon the senses, we call our ideas the objects of our thought, because we cannot discern anything else from whose action they should arise: yet this does not hinder but that such of them at least, as come upon us involuntarily, may proceed from something in our humors, or animal circulation, conveying them to the mind; and were we as familiarly acquainted with these as we are with visible bodies, we should call them the objects.

3. Our manner of talking, that the senses convey ideas from objects without us, implies as if ideas were something brought from thence to the mind: but whether they really be so, is more than we know, or whether there be any resemblance between them and the bodies exhibiting them. The sense of hearing bids the fairest for such conveyance; for when you strike upon a bell, you put it thereby into a tremulous motion, which agitates the air with the like tremors; and those again generate similar vibrations in the auditory nerves, and perhaps propagate the same onward to that fibre, or last substance, whose modification is the idea affecting us with sound.

Colors seem agreed on all hands to be not existing in bodies after the same manner as they appear to our apprehension. The learned tell you they are nothing but a certain configuration in the surfaces of objects, adapted to reflect some particular rays of light and absorb the rest and though the unlearned speak of colors as being in the bodies exhibiting them, I take this to proceed only from the equivocal sense of the word color, which stands indifferently either for the sensation, or the quality of exciting it. For if you question the most illiterate person breathing, you will always find him ascribing the sensation to the mind alone, and the quality of raising it to the object alone, though perhaps he might call both by the name of color: but he will never fancy the rose has any sensation of its own redness, nor, could your mind and

sensory be laid open to his view when you look upon a rose, would he ever expect to find any redness there. The like may be said of heat and cold, which signify as well our sensations as the modifications of bodies occasioning them: therefore, though we say the fire is hot, and makes us hot, we do not mean the same thing by the same word in both places. When nurse sets her child's pannikin upon the fire to warm, she does not imagine the fire will infuse a sensation of heat into the pap, but only will communicate a like quality of raising warmth in her, should she thrust her finger or the tip of her tongue into it: and when she feels herself warmed by the fire, she never dreams that this feeling will impart its likeness to the child, without application of her warm hands, or a double clout having received the like quality of warming from the fire. When we talk of fire melting metals, or burning combustibles by the intenseness of its heat, we mean the quality it has of producing the alterations we see made in those bodies; and this we denominate heat, from that best known effect we find it have upon ourselves, in raising a burning smart on our flesh, whenever we approach near enough. Therefore, those, who would find fault with us for attributing color, heat, and cold, to inanimate bodies, take us up before we were down; for by such expressions we do not understand the sensations, but the qualities giving rise to them, which qualities really belong to the bodies so that I shall stand by my plain neighbors in maintaining snow to be white, fire hot, ice cold, lilies sweet, poppies stinking, pork savory, wormwood bitter, and the like, which they may justly do, without offence either to propriety of speech,' or to sound philosophy.

4. We are not troubled with the like shrewd objections against pleasure and pain, satisfaction and uneasiness, because those are commonly appropriated to the perceptions of the mind, and not spoken of as residing in bodies without us. Yet we lay ourselves open to criticism here too, as often as we talk of a pain in our toes, or a tickling in the palms of our hands, for it might be alleged the limbs are incapable of feeling either, and can only raise sensations of them in the mind. And we might as justly be charged with incorrectness, in complaining of our mind being uneasy, and our bed being uneasy; but our defence shall be, that the term carries a different force in the two parts of this sentence; for every child knows that if the bed becomes uneasy by the feathers clotting together into hard knobs, it is not because the lumps give uneasiness to the bed itself, but because they will make any one uneasy that shall lie upon them. But though pleasure and pain be perceptions, yet we may have an idea of them in their

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absence, or even in the presence of their contraries for we often remember past pleasures, when gone from us, with regret, and think of an evil we have escaped with joy at the deliverance; and this regret, or joy increases in proportion to the strength and clearness we have of the enjoyment or suffering, we now expect to feel no more.

Magnitude, figure, and motion, are reputed both by learned and vulgar to reside in the bodies wherein we observe them: yet it cannot be denied, that they suffer alterations in their conveyance to the mind, whether that be made through the sight, or the touch; they being all motion in the rays of light, the organs or other channels wherealong they pass, and that a different kind of motion from any in the bodies themselves. Nor, on arriving at the seat of the mind, can we say they reassume the same form they had at first setting out: magnitude assuredly does not, for when we look upon the cupola of St. Paul's, we cannot suppose anything within us of equal size with the object it represents; nor do we know whether there be anything of similar figure: and when we see a chariot drive swiftly before us, it is hardly probable, that the ends of our fibres imitate that whirling motion we discern in the wheels. But since it is the received opinion that magnitude, figure, and motion, are in the bodies such as we apprehend them to be, I shall take it for granted, nor shall I urge the changes they may receive in their passage to the mind as an argument to the contrary, because I know that in other cases, ideas may be conveyed by mediums very dissimilar to themselves when we read, or hear read, the description of a palace, or a garden, a battle, or a procession, there is nothing in the letters we look upon, or the sounds we hear uttered, at all resembling the scenes they describe; nevertheless, we have a full and clear conception of all the circumstances relating to them, conveyed either way to our understanding. As for solidity, when distinguished from hardness, I apprehend we have no direct sensation of that, but gather it from our observation of the resistance of bodies against one another, and of their constantly thrusting them away before they can enter into their places.

5. Sensations from external objects come to us ordinarily through certain mediums, either of light, air, or effluvia, feeling only excepted, which, for the most part, requires that the substance exciting it should lie in contact with some part of our body; yet, things intensely hot, or cold, we can feel at a distance. But, when the causes of sensation have reached the surface of our body, we must not think they have done their business there, for perception lies not at the eyes, or the ears, or the