He came into the world as Cassius Marcellus Clay Jr. on Jan. 17, 1942, in Louisville, Ky., the son of Cassius Marcellus Clay Sr., a handsome, loquacious sign painter, and his wife, Odessa Grady Clay, a church-going woman who tried to instill into her two sons the virtues of hard work, humility and respect for their elders. He departed this mortal coil in a Phoenix hospital on Friday as Muhammad Ali, 74, arguably the foremost heavyweight champion ever, and the most widely know