after man, that which has the most intelligence: this is further
confirmed, by the name he bears in the soil, to which he is indigenous,
which is _ourang outang_, or the man beast. There is, therefore, every
reason to believe that it is entirely in the brain, that consists the
difference, that is found not only between man and beasts, but also
between the man of wit, and the fool: between the thinking man, and he
who is ignorant; between the man of sound understanding, and the madman:
a multitude of experience, serves to prove, that those persons who are
most accustomed to use their intellectual faculties, have their brain
more extended than others: the same has been remarked of watermen, that
they have arms much longer than other men.

However this may be, the sensibility of the brain, and all its parts, is
a fact: if it be asked, whence comes this property? We shall reply, it
is the result of an arrangement, of a combination, peculiar to the
animal: it is thus that milk, bread, wine, change themselves in the
substance of man, who is a sensible being: this insensible matter
becomes sensible, in combining itself with a sensible whole. Some
philosophers think that sensibility is a universal quality of matter: in
this case, it would be useless to seek from whence this property is
derived, as we know it by its effects. If this hypothesis be admitted,
in like manner as two kinds of motion are distinguished in Nature, the
one called _live_ force, the other _dead_, or _inert_ force, two sorts
of sensibility will be distinguished, the one active or alive, the other
inert or dead. Then to animalize a substance, is only to destroy the
obstacles that prevent its being active or sensible. In fact,
sensibility is either a quality which communicates itself like motion,
and which is acquired by combination; or this sensibility is a property
inherent in all matter: in both, or either case, an unextended being,
without parts, such as the human soul is said to be, can neither be the