Mark Twain? George Carlin? Yul Brynner? Jean Cocteau? Bob Gray? Dilbert? Scott Adams? Anonymous? Question for Quote Investigator: Logic and careful reasoning are the ingredients of a constructive argument. Acrimony and irrationality are the elements of a fruitless argument. The celebrated humorist Mark Twain supposedly formulated the following cautionary remark. Here are two versions: (1) …