Begging the question — roughly, positing in the premises what is to be proved in the conclusion — is a perplexing fallacy.1 Are not question-begging arguments valid? Yes, we may find ourselves saying, but they are fallacious despite their validity, owing to their inability to establish the truth of a conclusion which is not already known. But are not question-begging arguments sometimes effective in bringing an audience to an awareness of the truth of the conclusion ? How can a dialectical maneuver which is capable of effecting epistemic progress be a fallacy, an illegitimate maneuver? In such cases of success, we can reply, the audience was simply in need of some logical coaching — a question-begging argument is of its very nature ill-suited for producing new knowledge in someone who is being fully rational. But then are not all valid arguments question-begging, since the conclusions are at least implicitly contained in the premises in such a way that a fully rational individual can never augment his knowledge through such arguments? No, we may answer, only those valid arguments in which the proposition constituting the conclusion appears, whether distinguised or not, as a distinct premise are question-begging; if several premises go together to imply a conclusion, the argument does not beg the question, But why is it legitimate to posit premises which more-or-less implicitly contain the conclusion, while it is illegitimate to posit premises which more-or-less explicitly contain the conclusion ? Because, we are tempted to say, a question-begging argument is one in which what is to be proved in the conclusion is posited in the premises, and this positing must be more-or-less explicit in order for a fallacy to be committed!