One of Augustine's favorite lessons was the story of Jesus asking that the person without sin cast the first stone at the woman caught in adultery. As a spiritual practice, carry a small stone in your pocket or purse and call it the First Stone or the Hypocrite Stone. When you find yourself criticizing others for lying or misrepresenting the truth, reach into your pocket and turn the stone three times, recalling that no matter how reprehensible the speaker is, you are not worthy to cast it.

Tom Cowan in The Way of the Saints