Chastity takes its origin in the heart, and its exterior practice consists in regulating and purifying the senses; this is why it is lost by means of all the external senses, as well as by the thoughts of the mind, and the desires of the heart. Thus, every sensation which we allow ourselves regarding an immodest object, or with a spirit of immodesty, is really an unchaste act, and the Apostle recommended the first Christians not even to mention the vice amongst them. Bees not only do not touch a body in a state of putrefaction, but they fly from the bad smell which it exhales.
Remark, I beseech you, what holy Scripture tells us of the Spouse of the Canticles. Everything is mysterious in them. Myrrh distils from her hands, and you know that this liquor preserves from corruption; her lips are bordered by a red riband, and that teaches us that modesty blushes at words, even when they are ever so little indecent; her eyes are compared to the eyes of the dove, on account of their purity; she wears earrings of gold, and that metal is also a symbol of purity; her nose is compared to a cedar of Lebanon, the odour of which is exquisite, and its wood incorruptible. What does all that mean? That the soul should be, in all its senses, devout, chaste, open, pure, and honourable.
- St. Francis de Sales, Introduction to the Devout Life, "How to Preserve Chastity".