class="dialog">HYL. I own the very SENSATION of resistance, which is all you immediately perceive, is not in the body; but the CAUSE of that sensation is.

PHIL. But the causes of our sensations are not things immediately perceived, and therefore are not sensible. This point I thought had been already determined.

HYL. I own it was; but you will pardon me if I seem a little embarrassed: I know not how to quit my old notions.

PHIL. To help you out, do but consider that if EXTENSION be once acknowledged to have no existence without the mind, the same must necessarily be granted of motion, solidity, and gravity; since they all evidently suppose extension. It is therefore superfluous to inquire particularly concerning each of them. In denying extension, you have denied them all to have any real existence.

HYL. I wonder, Philonous, if what you say be true, why those philosophers who deny the Secondary Qualities any real existence should yet attribute it to the Primary. If there is no difference between them, how can this be accounted for?

PHIL. It is not my business to account for every opinion of the philosophers. But, among other reasons which may be assigned for this, it seems probable that pleasure and pain being rather annexed to the former than the latter may be one. Heat and cold, tastes and smells, have something more vividly pleasing or disagreeable than the ideas of extension, figure, and motion affect us with. And, it being too visibly absurd to hold that pain or pleasure can be in an unperceiving substance, men are more easily weaned from believing the external existence of the Secondary than the Primary Qualities. You will be satisfied there is something in this, if you recollect the difference you made between an intense and more moderate degree of heat; allowing the one a real existence, while you denied it to the other. But, after all, there is no rational ground for that distinction; for, surely an indifferent sensation is as truly a SENSATION as one more pleasing or painful; and consequently should not any more than they be supposed to exist in an unthinking subject.

HYL. It is just come into my head, Philonous, that I have somewhere heard of a distinction between absolute and sensible extension. Now, though it be acknowledged that GREAT and SMALL, consisting merely in the relation which other extended beings have to the parts of our own bodies, do not really inhere in the substances themselves; yet nothing obliges us to hold the same with regard to ABSOLUTE EXTENSION, which is something abstracted from GREAT and SMALL, from this or that particular magnitude or figure. So likewise as to motion; SWIFT and SLOW are altogether relative to the succession of ideas in our own minds. But, it doth not follow, because those modifications of motion exist not without the mind, that therefore absolute motion abstracted from them doth not.

PHIL. Pray what is it that distinguishes one motion, or one part of extension, from another? Is it not something sensible, as some degree of swiftness or slowness, some certain magnitude or figure peculiar to each?

HYL. I think so.

PHIL. These qualities, therefore, stripped of all sensible properties, are without all specific and numerical differences, as the schools call them.

HYL. They are.

PHIL. That is to say, they are extension in general, and motion in general.

HYL. Let it be so.

PHIL. But it is a universally received maxim that EVERYTHING WHICH EXISTS IS PARTICULAR. How then can motion in general, or extension in general, exist in any corporeal substance?

HYL. I will take time to solve your difficulty.

PHIL. But I think the point may be speedily decided. Without doubt you can tell whether you are able to frame this or that idea. Now I am content to put our dispute on this issue. If you can frame in your thoughts a distinct ABSTRACT IDEA of motion or extension, divested of all those sensible modes, as swift and slow, great and small, round and square, and the like, which are acknowledged to exist only in the mind, I will then yield the point you contend for. But if you cannot, it will be unreasonable on your side to insist any longer upon what you have no notion of.

HYL. To confess ingenuously, I cannot.

PHIL. Can you even separate the ideas of extension and motion from the ideas of all those qualities which they who make the distinction term SECONDARY?

HYL. What! is it not an easy matter to consider extension and motion by themselves, abstracted from all other sensible qualities? Pray how do the mathematicians treat of them?

PHIL. I acknowledge, Hylas, it is not difficult to form general propositions and reasonings about those qualities, without mentioning any other; and, in this sense, to consider or treat of them abstractedly. But, how doth it follow that, because I can pronounce the word MOTION by itself, I can form the idea of it in my mind exclusive of body? or, because theorems may be made of extension and figures, without any mention of GREAT or SMALL, or any other sensible mode or quality, that therefore it is possible such an abstract idea of extension, without any particular size or figure, or sensible quality, should be distinctly formed, and apprehended by the mind? Mathematicians treat of quantity, without regarding what other sensible qualities it is attended with, as being altogether indifferent to their demonstrations. But, when laying aside the words, they contemplate the bare ideas, I believe you will find, they are not the pure abstracted ideas of extension.

HYL. But what say you to PURE INTELLECT? May not abstracted ideas be framed by that faculty?

PHIL. Since I cannot frame abstract ideas at all, it is plain I cannot frame them by the help of PURE INTELLECT; whatsoever faculty you understand by those words. Besides, not to inquire into the nature of pure intellect and its spiritual objects, as VIRTUE, REASON, GOD, or the like, thus much seems manifest—that sensible things are only to be perceived by sense, or represented by the imagination. Figures, therefore, and extension, being originally perceived by sense, do not belong to pure intellect: but, for your farther satisfaction, try if you can frame the idea of any figure, abstracted from all particularities of size, or even from other sensible qualities.

HYL. Let me think a little—I do not find that I can.

PHIL. And can you think it possible that should really exist in nature which implies a repugnancy in its conception?

HYL. By no means.

PHIL. Since therefore it is impossible even for the mind to disunite the ideas of extension and motion from all other sensible qualities, doth it not follow, that where the one exist there necessarily the other exist likewise?

HYL. It should seem so.

PHIL. Consequently, the very same arguments which you admitted as conclusive against the Secondary Qualities are, without any farther application of force, against the Primary too. Besides, if you will trust your senses, is it not plain all sensible qualities coexist, or to them appear as being in the same place? Do they ever represent a motion, or figure, as being divested of all other visible and tangible qualities?

HYL. You need say no more on this head. I am free to own, if there be no secret error or oversight in our proceedings hitherto, that all sensible qualities are alike to be denied existence without the mind. But, my fear is that I have been too liberal in my former concessions, or overlooked some fallacy or other. In short, I did not take time to think.

PHIL. For that matter, Hylas, you may take what