_Hyl._ True: but, beside all that, do you not think the sight suggests something of _outness_ or _distance_?
_Phil._ Upon approaching a distant object, do the visible size and figure change perpetually, or do they appear the same at all distances?
_Hyl._ They are in a continual change.
_Phil._ Sight therefore doth not suggest, or any way inform you, that the visible object you immediately perceive exists at a distance(812), or will be perceived when you advance farther onward; there being a continued series of visible objects succeeding each other during the whole time of your approach.
_Hyl._ It doth not; but still I know, upon seeing an object, what object I shall perceive after having pa.s.sed over a certain distance: no matter whether it be exactly the same or no: there is still something of distance suggested in the case.
_Phil._ Good Hylas, do but reflect a little on the point, and then tell me whether there be any more in it than this: From the ideas you actually perceive by sight, you have by experience learned to collect what other ideas you will (according to the standing order of nature) be affected with, after such a certain succession of time and motion.
_Hyl._ Upon the whole, I take it to be nothing else.
_Phil._ Now, is it not plain that if we suppose a man born blind was on a sudden made to see, he could at first have no experience of what may be _suggested_ by sight?
_Hyl._ It is.
_Phil._ He would not then, according to you, have any notion of distance annexed to the things he saw; but would take them for a new set of sensations, existing only in his mind?
_Hyl._ It is undeniable.
_Phil._ But, to make it still more plain: is not _distance_ a line turned endwise to the eye(813)?
_Hyl._ It is.
_Phil._ And can a line so situated be perceived by sight?
_Hyl._ It cannot.
_Phil._ Doth it not therefore follow that distance is not properly and immediately perceived by sight?
_Hyl._ It should seem so.
_Phil._ Again, is it your opinion that colours are at a distance(814)?
_Hyl._ It must be acknowledged they are only in the mind.
_Phil._ But do not colours appear to the eye as coexisting in the same place with extension and figures?
_Hyl._ They do.
_Phil._ How can you then conclude from sight that figures exist without, when you acknowledge colours do not; the sensible appearance being the very same with regard to both?
_Hyl._ I know not what to answer.
_Phil._ But, allowing that distance was truly and immediately perceived by the mind, yet it would not thence follow it existed out of the mind. For, whatever is immediately perceived is an idea(815): and can any idea exist out of the mind?
_Hyl._ To suppose that were absurd: but, inform me, Philonous, can we perceive or know nothing beside our ideas(816)?
_Phil._ As for the rational deducing of causes from effects, that is beside our inquiry. And, by the senses you can best tell whether you perceive anything which is not immediately perceived. And I ask you, whether the things immediately perceived are other than your own sensations or ideas? You have indeed more than once, in the course of this conversation, declared yourself on those points; but you seem, by this last question, to have departed from what you then thought.
_Hyl._ To speak the truth, Philonous, I think there are two kinds of objects:-the one perceived immediately, which are likewise called _ideas_; the other are real things or external objects, perceived by the mediation of ideas, which are their images and representations. Now, I own ideas do not exist without the mind; but the latter sort of objects do. I am sorry I did not think of this distinction sooner; it would probably have cut short your discourse.
_Phil._ Are those external objects perceived by sense, or by some other faculty?
_Hyl._ They are perceived by sense.
_Phil._ How! Is there anything perceived by sense which is not immediately perceived?
_Hyl._ Yes, Philonous, in some sort there is. For example, when I look on a picture or statue of Julius Caesar, I may be said after a manner to perceive him (though not immediately) by my senses.
_Phil._ It seems then you will have our ideas, which alone are immediately perceived, to be pictures of external things: and that these also are perceived by sense, inasmuch as they have a conformity or resemblance to our ideas?
_Hyl._ That is my meaning.
_Phil._ And, in the same way that Julius Caesar, in himself invisible, is nevertheless perceived by sight; real things, in themselves imperceptible, are perceived by sense.
_Hyl._ In the very same.
_Phil._ Tell me, Hylas, when you behold the picture of Julius Caesar, do you see with your eyes any more than some colours and figures, with a certain symmetry and composition of the whole?
_Hyl._ Nothing else.
_Phil._ And would not a man who had never known anything of Julius Caesar see as much?
_Hyl._ He would.
_Phil._ Consequently he hath his sight, and the use of it, in as perfect a degree as you?
_Hyl._ I agree with you.
_Phil._ Whence comes it then that your thoughts are directed to the Roman emperor, and his are not? This cannot proceed from the sensations or ideas of sense by you then perceived; since you acknowledge you have no advantage over him in that respect. It should seem therefore to proceed from reason and memory: should it not?
_Hyl._ It should.
_Phil._ Consequently, it will not follow from that instance that anything is perceived by sense which is not immediately perceived. Though I grant we may, in one acceptation, be said to perceive sensible things mediately by sense: that is, when, from a frequently perceived connexion, the immediate perception of ideas by one sense _suggests_ to the mind others, perhaps belonging to another sense, which are wont to be connected with them. For instance, when I hear a coach drive along the streets, immediately I perceive only the sound; but, from the experience I have had that such a sound is connected with a coach, I am said to hear the coach.
It is nevertheless evident that, in truth and strictness, nothing can be _heard_ but _sound_; and the coach is not properly perceived by sense, but suggested from experience. So likewise when we are said to see a red-hot bar of iron; the solidity and heat of the iron are not the objects of sight, but suggested to the imagination by the colour and figure which are properly perceived by that sense. In short, those things alone are actually and strictly perceived by any sense, which would have been perceived in case that same sense had then been first conferred on us. As for other things, it is plain they are only suggested to the mind by experience, grounded on former perceptions. But, to return to your comparison of Caesar"s picture, it is plain, if you keep to that, you must hold the real things, or archetypes of our ideas, are not perceived by sense, but by some internal faculty of the soul, as reason or memory. I would therefore fain know what arguments you can draw from reason for the existence of what you call _real things_ or _material objects_. Or, whether you remember to have seen them formerly as they are in themselves; or, if you have heard or read of any one that did.
_Hyl._ I see, Philonous, you are disposed to raillery; but that will never convince me.
_Phil._ My aim is only to learn from you the way to come at the knowledge of _material beings_. Whatever we perceive is perceived immediately or mediately: by sense, or by reason and reflexion. But, as you have excluded sense, pray shew me what reason you have to believe their existence; or what _medium_ you can possibly make use of to prove it, either to mine or your own understanding.
_Hyl._ To deal ingenuously, Philonous, now I consider the point, I do not find I can give you any good reason for it. But, thus much seem pretty plain, that it is at least possible such things may really exist. And, as long as there is no absurdity in supposing them, I am resolved to believe as I did, till you bring good reasons to the contrary.
_Phil._ What! Is it come to this, that you only _believe_ the existence of material objects, and that your belief is founded barely on the possibility of its being true? Then you will have me bring reasons against it: though another would think it reasonable the proof should lie on him who holds the affirmative. And, after all, this very point which you are now resolved to maintain, without any reason, is in effect what you have more than once during this discourse seen good reason to give up. But, to pa.s.s over all this; if I understand you rightly, you say our ideas do not exist without the mind, but that they are copies, images, or representations, of certain originals that do?
_Hyl._ You take me right.
_Phil._ They are then like external things(817)?