Mr. Mooney and Mr. Gregory, two of the most influential living stand-ups, split the stage for the evening. Mr. Mooney, who wrote for Richard Pryor, "In Living Color," and "Chappelle's Show," has always been a forceful social critic on race issues. Mr. Gregory was the first African-American comedian to be called over to the couch on "The Tonight Show," and over his 60-plus year career, he's mixed social activism with biting comedy.