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?

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.