The definition given by Chrysippus, who
derived it from Cleanthes, to the effect that it is the
science of speaking rightly,
amounts to the same thing.
The same philosopher also gives other definitions,
but they concern problems of a different character
from that on which we are now engaged. Another
definition defines oratory as the power of persuading
men to do what ought to be done,
and yields practically
the same sense save that it limits the art to the result
which it produces.