a pleasure and a bitter taste is a pain, and that pleasure and pain are mental. The same argument
applies to odours, since they are pleasant or unpleasant.
Hylas makes a vigorous effort to rescue sound, which, he says, is motion in air, as may be seen
from the fact that there are no sounds in a vacuum. We must, he says, "distinguish between sound
as it is perceived by us, and as it is in itself; or between the sound which we immediately perceive
and that which exists without us." Philonous points out that what Hylas calls "real" sound, being a
movement, might possibly be seen or felt, but can certainly not be heard; therefore it is not sound
as we know it in perception. As to this, Hylas now concedes that "sounds too have no real being
without the mind."
They now come to colours, and here Hylas begins confidently: "Pardon me: the case of colours is
very different. Can anything be plainer than that we see them on the objects?" Substances existing
without the mind, he maintains, have the colours we see on them. But Philonous has no difficulty
in disposing of this view. He begins with the sunset clouds, which are red and golden, and points
out that a cloud, when you are close to it, has no such colours. He goes on to the difference made
by a microscope, and to the yellowness of everything to a man who has jaundice. And very small
insects, he says, must be able to see much smaller objects than we can see. Hylas thereupon says
that colour is not in the objects, but in the light; it is, he says, a thin fluid substance. Philonous
points out, as in the case of sound, that, according to Hylas, "real" colours are something different
from the red and blue that we see, and that this won't do.
Hereupon Hylas gives way about all secondary qualities, but continues to say that primary
qualities, notably figure and motion, are inherent in external unthinking substances. To this
Philonous replies that things look big when we are near them and small when we are far off, and
that a movement may seem quick to one man and slow to another.
At this point Hylas attempts a new departure. He made a mistake, he says, in not distinguishing
the object from the sensation; the act of perceiving he admits to be mental, but not what is
perceived; colours, for example, "have a real existence without the mind, in some unthinking
substance." To this Philonous replies: "That any immediate object of the senses--that is, any idea
or combination of ideas--should exist in an unthinking substance, or exterior to all minds, is in
itself an evi-