Begging The Question - Definition

Definition

The fallacy of petitio principii, or "begging the question", is committed "when a proposition which requires proof is assumed without proof", or more generally denotes when an assumption is used, "in some form of the very proposition to be proved, as a premise from which to deduce it". Thus, insofar as petitio principii refers to arguing for a conclusion that has already been assumed in the premise, this fallacy consists of "begging" the listener to accept the "question" (proposition) before the labor of logic is undertaken. The fallacy may be committed in various ways.

When the fallacy of begging the question is committed in a single step, it is sometimes called a hysteron proteron, as in the statement "Opium induces sleep because it has a soporific quality". Such fallacies may not be immediately obvious due to the use of synonyms or synonymous phrases; one way to beg the question is to make a statement first in concrete terms, then in abstract ones, or vice-versa. Another is to "bring forth a proposition expressed in words of Saxon origin, and give as a reason for it the very same proposition stated in words of Norman origin", as in this example: "To allow every man an unbounded freedom of speech must always be, on the whole, advantageous to the State, for it is highly conducive to the interests of the community that each individual should enjoy a liberty perfectly unlimited of expressing his sentiments".

When the fallacy of begging the question is committed in more than one step, it is sometimes referred to as circulus in probando or reasoning in a circle but incorrectly so, if this fallacy is considered under the definition Aristotle gave in Prior Analytics.

"Begging the question" can also refer to making an argument in which the premise "is different from the conclusion ... but is controversial or questionable for the same reasons that typically might lead someone to question the conclusion".

…eldom is anyone going to simply place the conclusion word-for-word into the premises … Rather, an arguer might use phraseology that conceals the fact that the conclusion is masquerading as a premise. The conclusion is rephrased to look different and is then placed in the premises. —Paul Herrick