PHIL. Pardon me, Hylas, if I am desirous clearly to apprehend your
notions, since this may much shorten our inquiry. Suffer me then to ask
you this farther question. Are those things only perceived by the senses
which are perceived immediately? Or, may those things properly be said to
be SENSIBLE which are perceived mediately, or not without the
intervention of others?

HYL. I do not sufficiently understand you.

PHIL. In reading a book, what I immediately perceive are the letters;
but mediately, or by means of these, are suggested to my mind the notions
of God, virtue, truth, &c. Now, that the letters are truly sensible
things, or perceived by sense, there is no doubt: but I would know
whether you take the things suggested by them to be so too.

HYL. No, certainly: it were absurd to think GOD or VIRTUE sensible
things; though they may be signified and suggested to the mind by
sensible marks, with which they have an arbitrary connexion.

PHIL. It seems then, that by SENSIBLE THINGS you mean those only
which can be perceived IMMEDIATELY by sense?

HYL. Right.

PHIL. Doth it not follow from this, that though I see one part of the
sky red, and another blue, and that my reason doth thence evidently
conclude there must be some cause of that diversity of colours, yet that
cause cannot be said to be a sensible thing, or perceived by the sense of
seeing?