Again it is scarcely necessary
for me to point out that like other arts it is based on
examination and practice. And if logic is an art, as
is generally agreed, rhetoric must also be an art, since
it differs from logic in species
rather than in genus.
Nor must I omit to point out that where it is possible
in any given subject for one man to act without art
and another with art, there must necessarily be an
art in connexion with that subject, as there must also
be in any subject in which the man who has received
instruction is the superior of him who has not.