Great art has dreadful manners? ?The hushed reverence of the gallery can fool you into believing masterpieces are visions that soothe, charm and beguile, but actually they are thugs. Merciless and wily, the greatest paintings grab you in a headlock and proceed in short order to re-arrange your sense of reality.? In inimitable style, our greatest historian and master storyteller Simon Schama makes an irresistible case for the power of art and its necessary place in our lives, examining art through the prism of the troubling life and works of Italian master painter, and murderer, Caravaggio. Selected from The Power of Art.