The things that make us luminaries of the world are these—our good works. What is good, moreover (provided it is true and full), does not love darkness: it rejoices in being seen and exults over the very recognition it receives. To Christian modesty it is not enough to be so but to also appear so. For its fullness should be so great that it flows out from the mind to the clothing and bursts out from the conscience to the outward appearance.
Source: ON THE DRESS OF WOMEN 2.13