I've been reading Secunda secundae of Saint Thomas Aquinas' Summa theologiae and I came across an interesting topic - women's cosmetics. Who would have thought that there would be a Thomistic position on make-up?
Thomas Aquinas is aware that St Cyprian of Carthage had some hard words for women who painted their faces "with the aid of yellow pigments, black powders or rouge, or by applying any dye that alters the natural features." According to Cyprian, "This is an assault on the Divine handiwork, a distortion of the truth." Cyprian seems convinced that cosmetic wearing women will "not see God" - by which I assume he means that they will go to Hell.
Thomas replies that the wearing of cosmetics is only a sin for women who wear cosmetics for the "sake of sensuous pleasure or in contempt of God" (II-II, q. 169, a. 2, ad. 2). In the case of married women: "If a married woman adorn herself in order to please her husband, she can do this without sin" (II-II, q. 169, a. 2, c). Thomas explains in detail that married women may adorn themselves moderately with clothing and with cosmetics in order to please their husbands.
So rest easy, ladies. Saint Thomas has made a theological defense for your lipstick so long as its not for the "sake of sensuous pleasure or in contempt of God."