d play of
his features, but also in his walk, nay, in every movement, however
slight it may be. One could perhaps discriminate from behind between a
blockhead, a fool, and a man of genius. A clumsy awkwardness
characterises every movement of the blockhead; folly imprints its mark
on every gesture, and so do genius and a reflective nature. Hence the
outcome of La Bruyere's remark: _Il n'y a rien de si delie, de si
simple, et de si imperceptible ou il n'y entrent des manieres, qui nous
decelent: un sot ni n'entre, ni ne sort, ni ne s'assied, ni ne se leve,
ni ne se tait, ni n'est sur ses jambes, comme un homme d'esprit_. This
accounts for, by the way, that instinct _stir et prompt_ which,
according to Helvetius, ordinary people have of recognising people of
genius and of running away from them. This is to be accounted for by the
fact that the larger and more developed the brain, and the thinner, in
relation to it, the spine and nerves, the greater not only is the
intelligence, but also at the same time the mobility and pliancy of all
the limbs; because they are controlled more immediately and decisively
by the brain; consequently everything depends more on a single thread,
every movement of which precisely expresses its purpose. The whole
matter is analogous to, nay dependent on, the fact that the higher an
animal stands in the scale of development, the easier can it be killed
by wounding it in a single place. Take, for instance, batrachia: they
are as heavy, clumsy, and slow in their movements as they are
unintelligent, and at the same time extremely tenacious of life. This is
explained by the fact that with a little brain they have a very thick
spine and nerves. But gait and movement of the arms are for the most
part functions of the brain; because the limbs receive their motion, and
even the slightest modification of it, from the brain through the medium
of the spinal nerves; and this is precisely why voluntary movements tire
us. This feeling of fatigue, like that of pain, has its seat in the
brain, and not as we suppose in the limbs, hence motion promotes sleep;
on the other hand, those motions that are not excited by the brain, that
is to say, the involuntary motions of organic life, of the heart and
lungs, go on without causing fatigue: and as thought as well as motion
is a function of the brain, the character of its activity is denoted in
both, according to the nature of the individual. Stupid people move like
lay f