77. To have full knowledge of what is foul is in the highest degree shameful. To see anything of this sort, if by chance it should happen, how dreadful that is! What, therefore, is displeasing to us in others, can that be pleasing in ourselves? Is not nature herself our teacher, who has formed to perfection every part of our body, so as to provide for what is necessary and to beautify and grace its form? However she has left plain and open to the sight those parts which are beautiful to look upon; among which, the head, set as it were above all, and the pleasant lines of the figure, and the appearance of the face are prominent, whilst their usefulness for work is ready to hand. But those parts in which there is a compliance with the necessities of nature, she has partly put away and hidden in the body itself, lest they should present a disgusting appearance, and partly, too, she has taught and persuaded us to cover them. Cic. de Off. I. 35.