ABSTRACT

Is the question, ‘What is one of the most useful pairs of question and answer?’, together with its answer, one of the most useful question and answer pairs? Suppose it is given as the question part of its own answer. Then it is an incorrect answer because it is so uninformative. But since all the correct answers will be highly useful, it is a highly useful question to ask after all. So it is correct to give it as part of its own answer only if it isn’t correct; and, if it isn’t correct to do so, it is.