Moreover, the arrangement of virtue according to right reason, and the transgression of it contrary to right reason, produce [in the former case] a tendency to the decorous as the final mark, and [in the latter] the frustration of it. The decorous however, is that which ought to be. But this does not require either addition or ablation; since it is that which it is requisite to be. But of the indecorous there are two species; one of which is excess, and the other defect. And excess indeed, is more, but deficiency is less, than is decorous. Virtue also, is a certain habit of the decorous. Hence it is directly, both a summit and a medium. For thus, things that are decorous are both media and summits. They are media indeed, because they fall between excess and deficiency; but they are summits, because they do not require either addition or ablation. For they are the very things themselves which they ought to be. Since however, the virtue of manners is conversant with the passions, but of the passions pleasure and pain are supreme, it is evident that virtue does not consist in extirpating the passions of the soul, pleasure and pain, but in co-harmonizing them. For neither does health, which is a certain apt mixture of the powers of the body, consist in expelling the cold and the hot, the moist and the dry; but in these being [appropriately] mingled together. For it is as it were, a certain symmetry of these. Thus too, in music, concord does not consist in expelling the sharp and the flat; but when these are co-harmonized, then concord is produced, and dissonance is exterminated. In a similar manner, the hot and the cold, the moist and the dry, being harmoniously mingled together, health is produced, and disease destroyed. But when anger, and desire are co-harmonized, the vices and the [other] passions are extirpated, and the virtues and manners are ingenerated. Deliberate choice however, in beautiful conduct, is the greatest peculiarity of the virtue of manners. For it is possible to use reason and power without virtue; but it is not possible to use deliberate choice without it. For deliberate choice indicates the dignity of manners. Hence also, the reasoning power subduing _by force_ anger and desire, produces continence and endurance. And again, when the reasoning power is violently dethroned by the irrational parts, then incontinence and effeminacy are produced. Such dispositions however, of the soul as these, are half-perfect virtues, and half-perfect vices. For the reasoning power of the soul is [according to its natural subsistence] in a healthy, but the irrational parts are in a diseased condition. And so far indeed, as anger and desire are governed and led by the rational part of the soul, continence and endurance become virtues; but so far as this is effected by violence, and not voluntarily, they become vices. For it is necessary that virtue should perform such things as are fit, not with pain, but with pleasure.