ose bodies abound with different humours, do not see the
same colours in every object that we do? From all which, should it not
seem to follow that all colours are equally apparent, and that none of
those which we perceive are really inherent in any outward object?

HYL. It should.

PHIL. The point will be past all doubt, if you consider that, in case
colours were real properties or affections inherent in external bodies,
they could admit of no alteration without some change wrought in the very
bodies themselves: but, is it not evident from what hath been said that,
upon the use of microscopes, upon a change happening in the burnouts of
the eye, or a variation of distance, without any manner of real
alteration in the thing itself, the colours of any object are
either changed, or totally disappear? Nay, all other circumstances
remaining the same, change but the situation of some objects, and they
shall present different colours to the eye. The same thing happens upon
viewing an object in various degrees of light. And what is more known
than that the same bodies appear differently coloured by candle-light
from what they do in the open day? Add to these the experiment of a prism
which, separating the heterogeneous rays of light, alters the colour of
any object, and will cause the whitest to appear of a deep blue or red to
the naked eye. And now tell me whether you are still of opinion that
every body hath its true real colour inhering in it; and, if you think it
hath, I would fain know farther from you, what certain distance and
position of the object, what peculiar texture and formation of the eye,
what degree or kind of light is necessary for ascertaining that true
colour, and distinguishing it from apparent ones.

HYL. I own myself entirely satisfied, that they are all equally
apparent, and that there is no such thing as colour really inhering in
external bodies, but that it is altogether in the light. And what
confirms me in this opinion is, that in proportion to the light colours
are still more or less vivid; and if there be no light, then are there no
colours perceived. Besides, allowing there are colours on external
objects, yet, how is it possible for us to perceive them? For no external
body affects the mind, unless it acts first on our organs of sense. But
the only action of bodies is motion; and motion cannot be communicated
otherwise than by impulse. A distant object therefore cannot act on the
eye; nor co