Seeing women when you go out is not forbidden, but it is sinful to desire them or to wish them to desire you, for it is not by tough or passionate feeling alone but by one’s gaze also that lustful desires mutually arise. And do not say that your hearts are pure if there is immodesty of the eye, because the unchaste eye carries the message of an impure heart. And when such hearts disclose their unchaste desires in a mutual gaze, even without saying a word, then it is that chastity suddenly goes out of their life, even though their bodies remain unsullied by unchaste acts.
Augustine