“HYLAS. Each visible object hath that color which we see in it.

PHILONOUS. How! is there anything visible but what we perceive by sight?

HYLAS. There is not. . . .

PHILONOUS. My reason for asking was, because in saying, each visible object hath that color which we see in it, you make visible objects to be corporeal substances; which imples either that corporeal substances are sensible qualities, or else that there is something beside sensible qualities perceived by sight: but, as this point was formerly agreed between us, and is still maintained by you, it is a clear consequence, that your corporeal substance is nothing distinct from sensible qualities.

HYLAS. You may draw as many absurd consequences as you please, and endeavor to perplex the plainest things, but you shall never persuade me out of my senses. I clearly understand my own meaning. . . .

PHILONOUS. What! are then the beautiful red and purple we see on yonder clouds really in them? Or do you imagine they have in themselves any other form than that of a dark mist or vapor?

HYLAS. I must own, Philonous, those colors are not really in the clouds as they seem to be at this distance. They are only apparent colors.

PHILONOUS. Apparent you call you them, how shall we distinguish these apparent colors from real?

HYLAS. Very easily. Those are to be thought apparent which, appearing only at a distance, vanish upon a nearer approach.

PHILONOUS. And those, I suppose, are to be thought real which are discovered by the most near and exact survey.

HYLAS. Right.

PHILONOUS. Is the nearest and exactest survey made by the help of a microscope, or by the naked eye?

HYLAS. By a microscope, doubtless.

PHILONOUS. But a microscope often discovers colors in an object different from those perceived by the unassisted sight. And, in case we had microscopes magnifying to any assigned degree, it is certain that no object whatsoever, viewed through them, would appear in the same color which it exhibits to the naked eyes.

HYLAS. And what will you conclude from all this? You cannot argue that there are really and naturally no colors on objects: because by artificial managements they may be altered, or made to vanish.

PHILONOUS. I think it may evidently be concluded from your own concessions, that all the colors we see with our naked eyes are only apparent as those on the clouds, since they vanish upon a more close and accurate inspection which is afforded us by a microscope.”

—George Berkeley, from Three Dialogues Between Hylas and Philonous, 1713.