Chapter XXV of Propriety in Attire
St. Paul wishes devout women (and the same must be understood of men) to be clothed in decent apparel, adorning themselves with modesty and sobriety (1 Timothy 2:9-10). Now the propriety of attire and other ornaments depends on the material, the form and the cleanliness. As to cleanliness, our clothes ought to be uniformly clean, and, as far as possible, we should not allow any sort of stains and dirt to remain upon them. Exterior cleanliness reflects in some wise interior probity. God himself demands bodily cleanliness in those that approach his altars, and have the chief care of devotion.
As to the material and the form of clothes, propriety is determined by various circuмstances of time, of age, of condition of life, of company, of occasion. Ordinarily we dress better on feast-days according to the importance of the festival; in seasons of penance, as in Lent, we lay aside fine apparel to a great extent; at weddings we wear wedding garments, and at funerals mourning; in the company of princes we put on richer garments, which we put off when we are at home.
— St. Francis de Sales, Introduction to the Devout Life