Begging The Question - Related Fallacies

Related Fallacies

Circular reasoning is a fallacy in which "the reasoner begins with what he or she is trying to end up with". The individual components of a circular argument can be logically valid because if the premises are true, the conclusion must be true, and will not lack relevance. However, circular reasoning is not persuasive because, if the conclusion is doubted, the premise which leads to it will also be doubted.

Begging the question is similar to the complex question or fallacy of many questions: questioning that presupposes something that would not be acceptable to everyone involved. For example, "Is Mary wearing a blue or a red dress?" is fallacious because it artificially restricts the possible responses to a blue or red dress. If the person being questioned wouldn't necessarily consent to those constraints, the question is fallacious.

Fallacies of Assumption are those errors in reasoning which occur when the assumptions on which an argument rests are not clearly distinguished from the judgments of which the argument consists. An assumption, in this connection, is anything we take for granted, but do not assert, about the subject matter of an argument. It is the equivalent of what we… speak of as the universe of discourse. Interpreted from this point of view, it is readily seen that an assumption is not an assertion, and forms no part of the asserted contents of an argument, although, as we have seen, it has a relation to the argument, a relation which is indicated with sufficient clearness by saying that it points out the sphere of reference in which what is asserted may or not be accepted. Now it is a misinterpretation of the relation between what an argument assumes and what it asserts that lies at the foundation of the fallacies that we have here to consider. Thus, when what is taken for granted or assumed is allowed to function in any part of an argument as an assertion or judgment, or when the assumption on which an argument proceeds is ambiguous, the resulting fallacy is one of assumption.

Petitio Princpii is the name of an argument which assumes the conclusion that is to be proved… “the surreptitious assumption of a truth you are pretending to prove.” Since, then, the fallacy is one of assumption… its source must be found, not in what is definitely asserted, but in the world of reality or existence in which what is asserted has a definite meaning or fulfillment, that is to say, in the universe of discourse from the standpoint of which the argument is interpreted… Whenever it exists, the fallacy directs attention to the fact that the truth of what an argument asserts depends in part upon what assumptions the argument makes; and, in view of the nature of an argument, it follows that when assumptions are put forward as reasons we necessarily fail to establish a conclusion, and fall into the merest dogmatism unless we are willing to have these assumptions called into question. … Now, when this happens, when in the course of argument assumptions take the place of reasoned judgments, the argument is fallacious because, for the reason assigned, it involves a petitio principii… When the fallacy of petitio principii is committed in a single step it is called… hysteron proteron… and when it involves more than a single step it is called circulus in probando or reasoning in a circle.

Closely connected with the foregoing is the fallacy of the Complex Question. By a complex question, in the broadest meaning of that term, is meant one that suggests its own answer. Any question, for instance, that forces us to select, and assert in our answer to it, one of the elements of the question itself, while some other possibility is really open, is complex in the sense in which that term is here employed. If, for example, one were to ask… if your favourite colour were red or blue, or if you had given up a particular bad habit, he would be guilty of the fallacy of the complex question, if, in each case, the alternatives, as a matter of fact, were more numerous than, or were in any way different from, those stated in the question. Any leading question which complicates an issue by over simplification is fallacious for the same reason. Now, in the light of what we have said with respect to the petitio principii, it is not difficult to see that the fallacy of the complex question is occasioned by the character of the assumption on which the question rests. In the petitio principii an assumption with respect to the subject-matter of an argument functions as a premise, in the complex question it is a similar assumption that shuts out some of the material possibilities of a situation and confines an issue within too narrow limits. As in the former case, so here, the only way of meeting the difficulty is to raise the previous question, that is, to call the assumption which lies back of the fallacy into question.

Ignoratio Elenchi, according to Aristotle, is a fallacy which arises from “ignorance of the nature of refutation.” In order to refute an assertion, Aristotle says we must prove its contradictory; the proof, consequently, of a proposition which stood in any other relation than that to the original, would be an ignoratio elenchi… Since Aristotle, the scope of the fallacy has been extended to include all cases of proving the wrong point… “I am required to prove a certain conclusion; I prove, not that, but one which is likely to be mistaken for it; in that lies the fallacy… For instance, instead of proving that ‘this person has committed an atrocious fraud,’ you prove that ‘this fraud he is accused of is atrocious;’” … The nature of the fallacy, then, consists in substituting for a certain issue another which is more or less closely related to it, and arguing the substituted issue. The fallacy does not take into account whether the arguments do or do not really support the substituted issue, it only calls attention to the fact that they do not constitute a proof of the original one… It is a particularly prevalent and subtle fallacy and it assumes a great variety of forms. But whenever it occurs and whatever form it takes, it is brought about by an assumption that leads the person guilty of it to substitute for a definite subject of inquiry another which is in close relation with it. In the petitio principii the fallacy may be described as an assumption of the premises; in the complex question, as an assumption of the answer; and in the ignoratio elenchi, as an assumption of the question at issue. —Arthur Ernest Davies, "Fallacies" in A Text-Book of Logic