Rhetoric   

great harm, that is a charge which may be made in common against all
good things except virtue, and above all against the things that are
most useful, as strength, health, wealth, generalship. A man can
confer the greatest of benefits by a right use of these, and inflict
the greatest of injuries by using them wrongly.
It is clear, then, that rhetoric is not bound up with a single
definite class of subjects, but is as universal as dialectic; it is
clear, also, that it is useful. It is clear, further, that its
function is not simply to succeed in persuading, but rather to
discover the means of coming as near such success as the circumstances
of each particular case allow. In this it resembles all other arts.
For example, it is not the function of medicine simply to make a man
quite healthy, but to put him as far as may be on the road to health;
it is possible to give excellent treatment even to those who can never
enjoy sound health. Furthermore, it is plain that it is the function
of one and the same art to discern the real and the apparent means of
persuasion, just as it is the function of dialectic to discern the
real and the apparent syllogism. What makes a man a 'sophist' is not
his faculty, but his moral purpose. In rhetoric, however, the term
'rhetorician' may describe either the speaker's knowledge of the art,
or his moral purpose. In dialectic it is different: a man is a
'sophist' because he has a certain kind of moral purpose, a
'dialectician' in respect, not of his moral purpose, but of his
faculty.
Let us now try to give some account of the systematic principles of
Rhetoric itself-of the right method and means of succeeding in the
object we set before us. We must make as it were a fresh start, and
before going further define what rhetoric is.
Part 2
Rhetoric may be defined as the faculty of observing in any given case
the available means of persuasion. This is not a function of any other
art. Every other art can instruct or persuade about its own particular
subject-matter; for instance, medicine about what is healthy and
unhealthy, geometry about the properties of magnitudes, arithmetic
about numbers, and the same is true of the other arts and sciences.
But rhetoric we look upon as the power of observing the means of
persuasion on almost any subject presented to us; and that is why we
say that, in its technical character, it is not concerned with any
special or definite class of subjects.
Of the modes of persuasion some belong strictly to the art of rhetoric
and some do not. By the latter I mean such things as are not supplied
by the speaker but are there at the outset-witnesses, evidence given
under torture, written contracts, and so on. By the former I mean such
as we can ourselves construct by means of the principles of rhetoric.
The one kind has merely to be used, the other has to be invented.
Of the modes of persuasion furnished by the spoken word there are
three kinds. The first kind depends on the personal character of the
speaker; the second on putting the audience into a certain frame of
mind; the third on the proof, or apparent proof, provided by the words
of the speech itself. Persuasion is achieved by the speaker's personal
character when the speech is so spoken as to make us think him
credible. We believe good men more fully and more readily than others:
this is true generally whatever the question is, and absolutely true
where exact certainty is impossible and opinions are divided. This
kind of persuasion, like the others, should be achieved by what the
speaker says, not by what people think of his character before he
begins to speak. It is not true, as some writers assume in their
treatises on rhetoric, that the personal goodness revealed by the
speaker contributes nothing to his power of persuasion; on the
contrary, his character may almost be called the most effective means
of persuasion he possesses. Secondly, persuasion may come through the
hearers, when the speech stirs their emotions. Our judgements when we
are pleased and friendly are not the same as when we are pained and
hostile. It is towards producing these effects, as we maintain, that