Part 16

PHIL. You ought not therefore to conclude that sensible objects are without the mind, from their appearance, or manner wherein they are perceived.

HYL. I acknowledge it. But doth not my sense deceive me in those cases?

PHIL. By no means. The idea or thing which you immediately perceive, neither sense nor reason informs you that it actually exists without the mind. By sense you only know that you are affected with such certain sensations of light and colours, &c. And these you will not say are without the mind.

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, 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 passed 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?

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?

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: 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?