then to ask you this farther question. Are those things only perceived by the senses which are perceived immediately? Or, may those things properly be said to be SENSIBLE which are perceived mediately, or not without the intervention of others?

HYL. I do not sufficiently understand you.

PHIL. In reading a book, what I immediately perceive are the letters; but mediately, or by means of these, are suggested to my mind the notions of God, virtue, truth, &c. Now, that the letters are truly sensible things, or perceived by sense, there is no doubt: but I would know whether you take the things suggested by them to be so too.

HYL. No, certainly: it were absurd to think GOD or VIRTUE sensible things; though they may be signified and suggested to the mind by sensible marks, with which they have an arbitrary connexion.

PHIL. It seems then, that by SENSIBLE THINGS you mean those only which can be perceived IMMEDIATELY by sense?

HYL. Right.

PHIL. Doth it not follow from this, that though I see one part of the sky red, and another blue, and that my reason doth thence evidently conclude there must be some cause of that diversity of colours, yet that cause cannot be said to be a sensible thing, or perceived by the sense of seeing?

HYL. It doth.

PHIL. In like manner, though I hear variety of sounds, yet I cannot be said to hear the causes of those sounds?

HYL. You cannot.

PHIL. And when by my touch I perceive a thing to be hot and heavy, I cannot say, with any truth or propriety, that I feel the cause of its heat or weight?

HYL. To prevent any more questions of this kind, I tell you once for all, that by SENSIBLE THINGS I mean those only which are perceived by sense; and that in truth the senses perceive nothing which they do not perceive IMMEDIATELY: for they make no inferences. The deducing therefore of causes or occasions from effects and appearances, which alone are perceived by sense, entirely relates to reason.

PHIL. This point then is agreed between us—That SENSIBLE THINGS ARE THOSE ONLY WHICH ARE IMMEDIATELY PERCEIVED BY SENSE. You will farther inform me, whether we immediately perceive by sight anything beside light, and colours, and figures; or by hearing, anything but sounds; by the palate, anything beside tastes; by the smell, beside odours; or by the touch, more than tangible qualities.

HYL. We do not.

PHIL. It seems, therefore, that if you take away all sensible qualities, there remains nothing sensible?

HYL. I grant it.

PHIL. Sensible things therefore are nothing else but so many sensible qualities, or combinations of sensible qualities?

HYL. Nothing else.

PHIL. HEAT then is a sensible thing?

HYL. Certainly.

PHIL. Doth the REALITY of sensible things consist in being perceived? or, is it something distinct from their being perceived, and that bears no relation to the mind?

HYL. To EXIST is one thing, and to be PERCEIVED is another.

PHIL. I speak with regard to sensible things only. And of these I ask, whether by their real existence you mean a subsistence exterior to the mind, and distinct from their being perceived?

HYL. I mean a real absolute being, distinct from, and without any relation to, their being perceived.

PHIL. Heat therefore, if it be allowed a real being, must exist without the mind?

HYL. It must.

PHIL. Tell me, Hylas, is this real existence equally compatible to all degrees of heat, which we perceive; or is there any reason why we should attribute it to some, and deny it to others? And if there be, pray let me know that reason.

HYL. Whatever degree of heat we perceive by sense, we may be sure the same exists in the object that occasions it.

PHIL. What! the greatest as well as the least?

HYL. I tell you, the reason is plainly the same in respect of both. They are both perceived by sense; nay, the greater degree of heat is more sensibly perceived; and consequently, if there is any difference, we are more certain of its real existence than we can be of the reality of a lesser degree.

PHIL. But is not the most vehement and intense degree of heat a very great pain?

HYL. No one can deny it.

PHIL. And is any unperceiving thing capable of pain or pleasure?

HYL. No, certainly.

PHIL. Is your material substance a senseless being, or a being endowed with sense and perception?

HYL. It is senseless without doubt.

PHIL. It cannot therefore be the subject of pain?

HYL. By no means.

PHIL. Nor consequently of the greatest heat perceived by sense, since you acknowledge this to be no small pain?

HYL. I grant it.

PHIL. What shall we say then of your external object; is it a material Substance, or no?

HYL. It is a material substance with the sensible qualities inhering in it.

PHIL. How then can a great heat exist in it, since you own it cannot in a material substance? I desire you would clear this point.

HYL. Hold, Philonous, I fear I was out in yielding intense heat to be a pain. It should seem rather, that pain is something distinct from heat, and the consequence or effect of it.

PHIL. Upon putting your hand near the fire, do you perceive one simple uniform sensation, or two distinct sensations?

HYL. But one simple sensation.

PHIL. Is not the heat immediately perceived?

HYL. It is.

PHIL. And the pain?

HYL. True.

PHIL. Seeing therefore they are both immediately perceived at the same time, and the fire affects you only with one simple or uncompounded idea, it follows that this same simple idea is both the intense heat immediately perceived, and the pain; and, consequently, that the intense heat immediately perceived is nothing distinct from a particular sort of pain.

HYL. It seems so.

PHIL. Again, try in your thoughts, Hylas, if you can conceive a vehement sensation to be without pain or pleasure.

HYL. I cannot.

PHIL. Or can you frame to yourself an idea of sensible pain or pleasure in general, abstracted from every particular idea of heat, cold, tastes, smells? &c.

HYL. I do not find that I can.

PHIL. Doth it not therefore follow, that sensible pain is nothing distinct from those sensations or ideas, in an intense degree?

HYL. It is undeniable; and, to speak the truth, I begin to suspect a very great heat cannot exist but in a mind perceiving it.

PHIL. What! are you then in that sceptical state of suspense, between affirming and denying?

HYL. I think I may be positive in the point. A very violent and painful heat cannot exist without the mind.

PHIL. It hath not therefore according to you, any REAL being?

HYL. I own it.

PHIL. Is it therefore certain, that there is no body in nature really hot?

HYL. I have not denied there is any real heat in bodies. I only say, there is no such thing as an intense real heat.

PHIL. But, did you not say before that all degrees of heat were equally real; or, if there was any difference, that the greater were more