reach from the tongue to the heart. Plato has a lively sense of
the manner in which sensation and motion are communicated from one part
of the body to the other, though he confuses the affections with the
organs. Hearing is a blow which passes through the ear and ends in the
region of the liver, being transmitted by means of the air, the brain,
and the blood to the soul. The swifter sound is acute, the sound which
moves slowly is grave. A great body of sound is loud, the opposite
is low. Discord is produced by the swifter and slower motions of two
sounds, and is converted into harmony when the swifter motions begin to
pause and are overtaken by the slower.

The general phenomena of sensation are partly internal, but the more
violent are caused by conflict with external objects. Proceeding by a
method of superficial observation, Plato remarks that the more sensitive
parts of the human frame are those which are least covered by flesh,
as is the case with the head and the elbows. Man, if his head had been
covered with a thicker pulp of flesh, might have been a longer-lived
animal than he is, but could not have had as quick perceptions. On the
other hand, the tongue is one of the most sensitive of organs; but then
this is made, not to be a covering to the bones which contain the marrow
or source of life, but with an express purpose, and in a separate mass.

Section 8.

We have now to consider how far in any of these speculations Plato
approximated to the discoveries of modern science. The modern physical
philosopher is apt to dwell exclusively on the absurdities of ancient
ideas about science, on the haphazard fancies and a priori assumptions
of ancient teachers, on their confusion of facts and ideas, on their
inconsistency and blindness to the most obvious phenomena. He measures
them not by what preceded them, but by what has followed them. He does
not consider that ancient physical philosophy was not a free enquiry,
but a growth, in which the mind was passive rather than active, and
was incapable of resisting the impressions which flowed in upon it.
He hardly allows to the notions of the ancients the merit of being the
stepping-stones by which he has himself risen to a higher knowledge. He
never reflects, how great a thing it was to have formed a conception,
however imperfect, either of the human frame as a whole, or of the world
as a whole. According to the view taken in these volumes the errors of
ancient physicists