Important, too, are the habits in which persons are trained, in the city or at home, and their daily food, by luxury enervating the soul, or fortifying it for strength. For the living out of doors, and single fare, and gymnastic exercises, and the morals of companions, produce the greatest effect in the way of vice and virtue. These causes are derived from our parents and the elements, rather than ourselves, provided that on our part there be no remissness, by keeping aloof from acts of duty. The animal cannot be in good condition unless the body possesses the better properties under its control; namely, health and correct perception, and strength and beauty.
Now the principles of beauty are a symmetry as regards its parts, and as regards the soul. For nature has arranged the body, like an instrument to be subservient to, and in harmony with, the subjects of life. The soul must likewise be brought into harmony with its analogous good qualities, namely, in the case of temperance, as the body is in the case of health; and in that of prudence, as in the case of correct perception; and in that of fortitude, as in the case of vigor and strength; and in that of justice, as in the case of beauty.
Nature, of course, furnishes their beginnings; but their continuation and maturation result from carefulness; those relating to the body, through the gymnastic and medical arts, those to the soul through instruction and philosophy. For these are the powers that nourish and give a tone to the body and soul by means of labor and gymnastic exercise, and pureness of diet; some through drug medication applied to the body, and others through discipline applied to the soul by means of punishments and reproaches; for by the encouragement they give strength and excite to an onward, movement, and exhort to beneficial deeds. The art of the gymnasium trainer, and its nearest approach, that of the medical man, do, on application to the body, reduce their powers to the utmost symmetry, purifying the blood, and equalizing the breath, so that, if there were there any diseased virulence, the powers of blood and breath may be vigorous; but music, and its leader, philosophy, which the laws and the gods ordained as regulators for the soul, accustom, persuade and partly compel the irrational to obey reason, and the two irrational, passion and desire, to become, the one mild, and the other quiet, so as not to be moved without reason, nor to be unmoved when the mind incites either to desire or enjoy something; for this is the definition of temperance, namely, docility and firmness. Intelligence and philosophy the highest in honor, after cleansing the soul from false opinions, have introduced knowledge, recalling the mind from excessive ignorance, and setting it free for the contemplation of divine things; in which to occupy oneself with self-sufficiency, as regards the affairs of a man, and with an abundance, for the commensurate period of life, is a happy state.