"Fallacy: An argument which seems conclusive, but is not so, is fallacious ; that is to say, deceptive. When such fallacies are designedly framed, for the purpose of misleading those to whom they are addressed, they are called sophisms. A fallacy takes place - 1st, When some one of the things affirmed in an argument, and which is important to the conclusion, is not true. 2d, When the connexion between one fact and another is not truly stated. 3d, When the words implied are used in one sense, in one part of the argument, and in another, in another part : or when the sense assigned to such terms is so vague or ambiguous, that an error slips in, as it were, unperceived, in the course of the argument."