Are not these shocking notions, and are not they subject to as many ridiculous inferences, as those you were obliged to renounce before in the case of sounds?

HYL. I frankly own, Philonous, that it is in vain to longer. Colours, sounds, tastes, in a word all those termed SECONDARY QUALITIES, have certainly no existence without the mind. But by this acknowledgment I must not be supposed to derogate, the reality of Matter, or external objects; seeing it is no more than several philosophers maintain, who nevertheless are the farthest imaginable from denying Matter. For the clearer understanding of this, you must know sensible qualities are by philosophers divided into PRIMARY and SECONDARY. The former are Extension, Figure, Solidity, Gravity, Motion, and Rest; and these they hold exist really in bodies. The latter are those above enumerated; or, briefly, ALL SENSIBLE QUALITIES BESIDE THE PRIMARY; which they assert are only so many sensations or ideas existing nowhere but in the mind. But all this, I doubt not, you are apprised of. For my part, I have been a long time sensible there was such an opinion current among philosophers, but was never thoroughly convinced of its truth until now.

PHIL. You are still then of opinion that EXTENSION and FIGURES are inherent in external unthinking substances?

HYL. I am.

PHIL. But what if the same arguments which are brought against Secondary Qualities will hold good against these also?

HYL. Why then I shall be obliged to think, they too exist only in the mind.

PHIL. Is it your opinion the very figure and extension which you perceive by sense exist in the outward object or material substance? HYL. It is.

PHIL. Have all other animals as good grounds to think the same of the figure and extension which they see and feel?

HYL. Without doubt, if they have any thought at all.

PHIL. Answer me, Hylas. Think you the senses were bestowed upon all animals for their preservation and well-being in life? or were they given to men alone for this end?

HYL. I make no question but they have the same use in all other animals.

PHIL. If so, is it not necessary they should be enabled by them to perceive their own limbs, and those bodies which are capable of harming them?

HYL. Certainly.

PHIL. A mite therefore must be supposed to see his own foot, and things equal or even less than it, as bodies of some considerable dimension; though at the same time they appear to you scarce discernible, or at best as so many visible points?

HYL. I cannot deny it.

PHIL. And to creatures less than the mite they will seem yet larger?

HYL. They will.

PHIL. Insomuch that what you can hardly discern will to another extremely minute animal appear as some huge mountain?

HYL. All this I grant.

PHIL. Can one and the same thing be at the same time in itself of different dimensions?

HYL. That were absurd to imagine.

PHIL. But, from what you have laid down it follows that both the extension by you perceived, and that perceived by the mite itself, as likewise all those perceived by lesser animals, are each of them the true extension of the mite's foot; that is to say, by your own principles you are led into an absurdity.

HYL. There seems to be some difficulty in the point.

PHIL. Again, have you not acknowledged that no real inherent property of any object can be changed without some change in the thing itself?

HYL. I have.

PHIL. But, as we approach to or recede from an object, the visible extension varies, being at one distance ten or a hundred times greater than another. Doth it not therefore follow from hence likewise that it is not really inherent in the object?

HYL. I own I am at a loss what to think.

PHIL. Your judgment will soon be determined, if you will venture to think as freely concerning this quality as you have done concerning the rest. Was it not admitted as a good argument, that neither heat nor cold was in the water, because it seemed warm to one hand and cold to the other?

HYL. It was.

PHIL. Is it not the very same reasoning to conclude, there is no extension or figure in an object, because to one eye it shall seem little, smooth, and round, when at the same time it appears to the other, great, uneven, and regular?

HYL. The very same. But does this latter fact ever happen?

PHIL. You may at any time make the experiment, by looking with one eye bare, and with the other through a microscope.

HYL. I know not how to maintain it; and yet I am loath to give up EXTENSION, I see so many odd consequences following upon such a concession.

PHIL. Odd, say you? After the concessions already made, I hope you will stick at nothing for its oddness. But, on the other hand, should it not seem very odd, if the general reasoning which includes all other sensible qualities did not also include extension? If it be allowed that no idea, nor anything like an idea, can exist in an unperceiving substance, then surely it follows that no figure, or mode of extension, which we can either perceive, or imagine, or have any idea of, can be really inherent in Matter; not to mention the peculiar difficulty there must be in conceiving a material substance, prior to and distinct from extension to be the SUBSTRATUM of extension. Be the sensible quality what it will—figure, or sound, or colour, it seems alike impossible it should subsist in that which doth not perceive it.

HYL. I give up the point for the present, reserving still a right to retract my opinion, in case I shall hereafter discover any false step in my progress to it.

PHIL. That is a right you cannot be denied. Figures and extension being despatched, we proceed next to MOTION. Can a real motion in any external body be at the same time very swift and very slow?

HYL. It cannot.

PHIL. Is not the motion of a body swift in a reciprocal proportion to the time it takes up in describing any given space? Thus a body that describes a mile in an hour moves three times faster than it would in case it described only a mile in three hours.

HYL. I agree with you.

PHIL. And is not time measured by the succession of ideas in our minds?

HYL. It is.

PHIL. And is it not possible ideas should succeed one another twice as fast in your mind as they do in mine, or in that of some spirit of another kind?

HYL. I own it.

PHIL. Consequently the same body may to another seem to perform its motion over any space in half the time that it doth to you. And the same reasoning will hold as to any other proportion: that is to say, according to your principles (since the motions perceived are both really in the object) it is possible one and the same body shall be really moved the same way at once, both very swift and very slow. How is this consistent either with common sense, or with what you just now granted?

HYL. I have nothing to say to it.

PHIL. Then as for SOLIDITY; either you do not mean any sensible quality by that word, and so it is beside our inquiry: or if you do, it must be either hardness or resistance. But both the one and the other are plainly relative to our senses: it being evident that what seems hard to one animal may appear soft to another, who hath greater force and firmness of limbs. Nor is it less plain that the resistance I feel is not in the body.