HYL. You must distinguish, Philonous, between sound as it is perceived by us, and as it is in itself; or (which is the same thing) between the sound we immediately perceive, and that which exists without us. The former, indeed, is a particular kind of sensation, but the latter is merely a vibrative or undulatory motion the air. PHIL. I thought I had already obviated that distinction, by answer I gave when you were applying it in a like case before. But, to say no more of that, are you sure then that sound is really nothing but motion? HYL. I am. PHIL. Whatever therefore agrees to real sound, may with truth be attributed to motion? HYL. It may. PHIL. It is then good sense to speak of MOTION as of a thing that is LOUD, SWEET, ACUTE, or GRAVE. HYL. _I_ see you are resolved not to understand me. Is it not evident those accidents or modes belong only to sensible sound, or SOUND in the common acceptation of the word, but not to sound in the real and philosophic sense; which, as I just now told you, is nothing but a certain motion of the air? PHIL. It seems then there are two sorts of sound--the one vulgar, or that which is heard, the other philosophical and real? HYL. Even so. PHIL. And the latter consists in motion? HYL. I told you so before. PHIL. Tell me, Hylas, to which of the senses, think you, the idea of motion belongs? to the hearing? HYL. No, certainly; but to the sight and touch. PHIL. It should follow then, that, according to you, real sounds may possibly be SEEN OR FELT, but never HEARD. HYL. Look you, Philonous, you may, if you please, make a jest of my opinion, but that will not alter the truth of things. I own, indeed, the inferences you draw me into sound something oddly; but common language, you know, is framed by, and for the use of the vulgar: we must not therefore wonder if expressions adapted to exact philosophic notions seem uncouth and out of the way. PHIL. Is it come to that? I assure you, I imagine myself to have gained no small point, since you make so light of departing from common phrases and opinions; it being a main part of our inquiry, to examine whose notions are widest of the common road, and most repugnant to the general sense of the world. But, can you think it no more than a philosophical paradox, to say that REAL SOUNDS ARE NEVER HEARD, and that the idea of them is obtained by some other sense? And is there nothing in this contrary to nature and the truth of things? HYL. To deal ingenuously, I do not like it. And, after the concessions already made, I had as well grant that sounds too have no real being without the mind. PHIL. And I hope you will make no difficulty to acknowledge the same of COLOURS. HYL. Pardon me: the case of colours is very different. Can anything be plainer than that we see them on the objects? PHIL. The objects you speak of are, I suppose, corporeal Substances existing without the mind? HYL. They are.