But inasmuch as happiness is a certain activity of soul in conformity with perfect
virtue, it is necessary to examine the nature of virtue. For this will probably assist us
in our investigation of the nature of happiness.
the true statesman seems to be one who has made a special study of goodness, since his aim
is to make the citizens good and law-abiding men—
witness the lawgivers of Crete
, and the other great legislators of history;
but if the study of virtue falls within the province of
Political Science, it is clear that in investigating virtue we shall be keeping to the
plan which we laid down at the outset.
Now the goodness that we have to consider is clearly human virtue, since the good or
happiness which we set out to seek is human good and human happiness.
But human virtue means in our view excellence of soul, not excellence of
body; also our definition of happiness is an activity of the soul.
Now if this is so, clearly it behoves the statesman to have some
acquaintance with psychology, just as the physician who is to heal the eye or the other parts of the body1
must know their anatomy. Indeed a foundation of science is even more
requisite for the statesman, inasmuch as politics is a higher and more honorable art than
medicine; but physicians of the better class devote much attention to the study of the
The student of politics2
therefore as well as the psychologist must study the nature of the soul,
though he will do so as an aid to politics, and only so far as is requisite for the
objects of enquiry that he has in view: to pursue the subject in further detail would
doubtless be more laborious than is necessary for his purpose.
Now on the subject of psychology some of the teaching current in extraneous
is satisfactory, and
may be adopted here: namely that the soul consists of two parts, one irrational and the
other capable of reason.4
（Whether these two parts are really distinct in
the sense that the parts of the body or of any other divisible whole are distinct, or
whether though distinguishable in thought as two they are inseparable in reality, like the
convex and concave sides of a curve, is a question of no importance for the matter in
Of the irrational part of the soul again
one division appears to be common to all living things, and of a vegetative nature: I
refer to the part that causes nutrition and growth; for we must assume that a vital
faculty of this nature exists in all things that assimilate nourishment, including
embryos—the same faculty being present also in the fully-developed organism
（this is more reasonable than to assume a different nutritive faculty in the
The excellence of this faculty
therefore appears to be common to all animate things and not peculiar to man; for it is
believed that this faculty or part of the soul is most active during sleep, but when they
are asleep you cannot tell a good man from a bad one （whence the saying that for
half their lives there is no difference between the happy and the miserable）.
This is a natural result of the fact that sleep is a
cessation of the soul from the functions on which its goodness or badness
depends—except that in some small degree certain of the sense-impressions may
reach into soul during sleep, and consequently the dreams of the good are better than
those of ordinary men.
We need not however pursue this
subject further, but may omit from consideration the nutritive part of the soul, since it
exhibits no specifically human excellence.
But there also appears to be another element in the soul, which, though irrational, yet
in a manner participates in rational principle. In self-restrained and unrestrained5
people we approve
their principle, or the rational part of their souls, because it urges them in the right
way and exhorts them to the best course; but their nature seems also to contain another
element beside that of rational principle, which combats and resists that principle.
Exactly the same thing may take place in the soul as
occurs with the body in a case of paralysis: when the patient wills to move his limbs to
the right they swerve to the left; and similarly in
unrestrained persons their impulses run counter to their principle. But whereas in the
body we see the erratic member, in the case of the soul we do not see it; nevertheless it
cannot be doubted that in the soul also there is an element beside that of principle,
which opposes and runs counter to principle （though in what sense the two are
distinct does not concern us here）.
second element also seems, as we said, to participate in rational principle; at least in
the self-restrained man it obeys the behest of principle—and no doubt in the
temperate and brave man it is still more amenable, for all parts of his nature are in
harmony with principle.
Thus we see that the irrational part, as well as the soul as a whole, is double. One
division of it, the vegetative, does not share in rational principle at all; the other,
the seat of the appetites and of desire in general, does in a sense participate in
principle, as being amenable and obedient to it （in the sense in fact in which we
speak of ‘paying heed’ to one's father and friends, not in the sense
of the term ‘rational’ in mathematics6
）. And that principle
can in a manner appeal to the irrational part, is indicated by our practice of admonishing
delinquents, and by our employment of rebuke and exhortation generally.
If the other hand it be more correct to speak of the appetitive part of the soul also as
rational, in that case it is the rational part which, as well as the whole soul, is
divided into two, the one division having rational principle in the proper sense and in
itself, the other obedient to it as a child to its father.
Now virtue also is differentiated in correspondence with this division of the soul. Some
forms of virtue are called intellectual virtues, others moral virtues: Wisdom or
intelligence and Prudence7
are intellectual, Liberality and
Temperance are moral virtues. When describing a man's moral character we do not say that
he is wise or intelligent, but gentle or temperate; but a wise man also is praised for his
, and praiseworthy dispositions we term virtues.