<p>IN ATHENS nearly 2,000 years ago, a grotesquely featured teacher – stout, bald, snub-nosed, thick-lipped, protruding eyes – called Socrates wandered the streets on the lookout for arguments. He was often successful. Many would regret stopping to discuss issues of the day with him because he would flummox them with denials and put-downs of what, until then, they had held to be certain and indubitable. Such teachers particularly attract the young, an age group unsure of many things and, if appropriately provoked, ripe for debate and intellectual challenge.</p>