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? 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. Howl Is there any thing 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.