Secondary Qualities did not subsist each alone by itself; but, that they
were not AT ALL without the mind. Indeed, in treating of figure
and motion we concluded they could not exist without the mind, because it
was impossible even in thought to separate them from all secondary
qualities, so as to conceive them existing by themselves. But then this
was not the only argument made use of upon that occasion. But (to pass by
all that hath been hitherto said, and reckon it for nothing, if you will
have it so) I am content to put the whole upon this issue. If you can
conceive it possible for any mixture or combination of qualities, or any
sensible object whatever, to exist without the mind, then I will grant it
actually to be so.

HYL. If it comes to that the point will soon be decided. What more easy
than to conceive a tree or house existing by itself, independent of, and
unperceived by, any mind whatsoever? I do at this present time conceive
them existing after that manner.

PHIL. How say you, Hylas, can you see a thing which is at the same time
unseen?

HYL. No, that were a contradiction.

PHIL. Is it not as great a contradiction to talk of CONCEIVING a
thing which is UNCONCEIVED?

HYL. It is.

PHIL. The, tree or house therefore which you think of is conceived by
you?