mind the sensation of SOUND. For, striking on the drum of the ear, it
causeth a vibration, which by the auditory nerves being communicated to
the brain, the soul is thereupon affected with the sensation called
SOUND.

PHIL. What! is sound then a sensation?

HYL. I tell you, as perceived by us, it is a particular sensation in
the mind.

PHIL. And can any sensation exist without the mind?

HYL. No, certainly.

PHIL. How then can sound, being a sensation, exist in the air, if by
the AIR you mean a senseless substance existing without the mind?

HYL. You must distinguish, Philonous, between sound as it is
perceived by us, and as it is in itself; or (which is the same thing)
between the sound we immediately perceive, and that which exists without
us. The former, indeed, is a particular kind of sensation, but the latter
is merely a vibrative or undulatory motion the air.

PHIL. I thought I had already obviated that distinction, by answer I
gave when you were applying it in a like case before. But, to say no more
of that, are you sure then that sound is really nothing but motion?

HYL. I am.

PHIL. Whatever therefore agrees to real sound, may with truth be