Timaeus

For whenever the humors which arise from acid and saline phlegms, and all humors that are bitter and bilious wander through the body and find no external vent but are confined within, and mingle their vapor with the movement of the soul and are blended therewith, they implant diseases of the soul of all kinds, varying in intensity and in extent; and as these humors penetrate to the three regions of the Soul, according to the region which they severally attack, they give rise to all varieties of bad temper and bad spirits, and they give rise to all manner of rashness and cowardice, and of forgetfulness also, as well as of stupidity. Furthermore, when, with men in such an evil condition, the political administration also is evil, and the speech in the cities, both public and private, is evil; and when, moreover, no lessons that would cure these evils are anywhere learnt from childhood,—thus it comes to pass that all of us who are wicked become wicked owing to two quite involuntary causes. And for these we must always blame the begetters more than the begotten, and the nurses more than the nurslings; yet each man must endeavor, as best he can, by means of nurture and by his pursuits and studies to flee the evil and to pursue the good. This, however, forms a separate subject of discussion. Again, it is reasonable and proper to set forth in turn the subject complementary to the foregoing, namely the remedial treatment of body and mind, and the causes which conserve this. For what is good merits description more than what is evil. All that is good is fair, and the fair is not void of due measure; wherefore also the living creature that is to be fair must be symmetrical. Of symmetries we distinguish and reason about such as are small, but of the most important and the greatest we have no rational comprehension. For with respect to health and disease, virtue and vice, there is no symmetry or want of symmetry greater than that which exists between the soul itself and the body itself. But as regards these, we wholly fail to perceive or reflect that, whenever a weaker and inferior type of body is the vehicle of a soul that is strong and in all ways great,—or conversely, when each of these two is of the opposite kind,—then the creature as a whole is not fair, seeing that it is unsymmetrical in respect of the greatest of symmetries; whereas a creature in the opposite condition is of all sights, for him who has eyes to see, the fairest and most admirable. A body, for example, which is too long in the legs, or otherwise disproportioned owing to some excess, is not only ugly, but, when joint effort is required, it is also the source of much fatigue and many sprains and falls by reason of its clumsy motion, whereby it causes itself countless evils.