Section — Vermeersch, Theologia Moralis
§ 1. What the Virtue of Modesty Is. What Immodest Acts Are
— Modesty is the very virtue of chastity which, by its own inclination, persuades us to avoid every signification of lust, and, in looks, kisses, and touches, to flee every suspect pleasure, so that we may manifest and profess chastity and continence. It can be called chastity zealous for sincerity and security. By the noble zeal of modesty all chastity is strengthened; angelic chastity is prepared.
II. Various acts are called immodest which, by their very external species, are akin to lustful acts, but can be called ambiguous, because they can be exercised on account of an honest cause, or a suspect cause, or even a strictly lustful one. When they are exercised without a cause perfectly excusing them, they are opposed to modesty.
III. Because, in this matter, speech not rarely occurs concerning songs and obscene pictures, observe that not every nude thing can be called obscene. But commonly an alluring nude is called obscene; and it can be described: A shameful manifestation of the soul or solicitation in nudity. (Cf. De castitate, n. 180, 181.)