Long ago Demosthenes had written: "We keep prostitutes for pleasure; we keep mistresses for the day to day needs of the body; we keep wives for the begetting of children and for the faithful guardianship of our homes. So long as a man supported his wife and family there was no shame whatsoever in extra- marital affairs."
C. Swindoll, Sanctity of Life, Word, 1990, p. 62.