only perceived by the senses which are perceived immediately? Or,
may those things properly be said to be  which are
perceived mediately, or not without the intervention of others?

     . I do not sufficiently understand you.

     . 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.

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

     . It seems then, that by <sensible things> you mean
those only which can be perceived <immediately> by sense?

     . Right.

     . 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?

     . It doth.

     . In like manner, though I hear variety of sounds, yet
I cannot be said to hear the causes of those sounds?

     . You cannot.

     . And when by my touch I perceive a thing to be hot
and heavy, I cannot say, with any truth or propriety, that I feel
the cause of its heat or weight?

     . To prevent any more questions of this kind, I tell
you once for all, that by <sensible things> I mean those only
which are perceived by sense; and that in truth the senses
perceive nothing which they do not perceive <immediately>: for
they make no {175} inferences. The deducing therefore of causes
or occasions from effects and appearances, which alone are
perceived by sense, entirely relates to reason.

     . This point then is agreed between us -- That
<sensible things are those only which are immediately perceived
by sense>. You will farther inform me, whether we immediately
perceive by sight anything beside light, and colours, and
figures; or by hearing, anything but sounds; by the palate,
anything beside tastes; by the smell, beside odours; or by the
touch, more than tangible qualities.

     . We do not.

     . It seems, therefore, that if you take away all
sensible qualities, there remains nothing sensible?

     . I grant it.

     . Sensible things therefore are {250} nothing else but
so many sensible qualities, or combinations of sensible
qualities?

     . Nothing else.

     .  then is a sensible thing?

     . Certainly.

     . Doth the  of sensible things consist in
being perceived? or, is it something distinct from their being
perceived, and that bears no relation to the mind?

     . To  is one thing, and to be  is
another.

     . I speak with regard to sensible things only. And of
these I ask, whether by their real existence you mean a
subsistence exterior to the mind, and distinct from their being
perceived?

     . I mean a real absolute being, distinct from, and
without any relation to, their being perceived.

     . Heat therefore, if it be allowed a real being, must
exist without the mind?

     . It must.

     . Tell me, Hylas, is this real existence equally
compatible to all degrees of heat, which we perceive; or is there
any reason why we should attribute it to some, and deny it to
others? And if there be, pray let me know that reason.

     . Whatever degree of heat we perceive by sense, we may
be sure the same exists in the object that occasions it.