Begging the question

Bust of Aristotle, whose Prior Analytics contained an early discussion of this fallacy.

Begging the question (or petitio principii, "assuming the initial point") is a type of logical fallacy in which the proposition to be proven is assumed implicitly or explicitly in the premise.

The first known definition in the West is by Aristotle around 350 BC, in his book Prior Analytics, where he classified it as a material fallacy. Begging the question is related to the circular argument, circulus in probando (Latin, "circle in proving") or circular reasoning, though these are considered absolutely different by Aristotle.^[1]

History

The term was translated into English from Latin in the 16th century. The Latin version, petitio principii, can be interpreted in different ways. Petitio (from peto), in the post-classical context in which the phrase arose, means "assuming" or "postulating," but in the older classical sense means "petition," "request," or "beseeching."^[2] Principii, genitive of principium, means "beginning," "basis," or "premise" (of an argument). Literally petitio principii means "assuming the premise" or "assuming the original point," or, alternately, "a request for the beginning or premise;" that is, the premise depends on the truth of the very matter in question.

The Latin phrase comes from the Greek en archei aiteisthai in Aristotle's Prior Analytics II xvi:

Begging or assuming the point at issue consists (to take the expression in its widest sense) [of] failing to demonstrate the required proposition. But there are several other ways in which this may happen; for example, if the argument has not taken syllogistic form at all, he may argue from premises which are less known or equally unknown, or he may establish the antecedent by means of its consequents; for demonstration proceeds from what is more certain and is prior. Now begging the question is none of these. [...] If, however, the relation of B to C is such that they are identical, or that they are clearly convertible, or that one applies to the other, then he is begging the point at issue.... [B]egging the question is proving what is not self-evident by means of itself...either because predicates which are identical belong to the same subject, or because the same predicate belongs to subjects which are identical.

Thomas Fowler believed that Petitio Principii would be more properly called Petitio Quæsiti, which is literally "begging the question".^[3]

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".^[4] 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,^[5][6] as in the statement "Opium induces sleep because it has a soporific quality".^[7] 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.^[7] 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",^[8] 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".^[9]

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^[5] but incorrectly so, if this fallacy is considered under the definition Aristotle gave in Prior Analytics.^[1]

"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".^[10]

.... seldom 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, ^[11]

Related fallacies

In informal situations, the term begging the question is often used in place of circular argument. In the formal context, however, begging the question holds a different meaning.^[1] In its shortest form, circular reasoning is the basing of two conclusions through a reversed premise of the first argument. Begging the question does not require any such reversal.

Begging the question is similar to the fallacy of many questions: a fallacy of technique that results from presenting evidence in support of a conclusion that is less likely to be accepted, rather than merely asserting the conclusion. A specific form of this is reducing an assertion to an instance of a more general assertion which is no more known to be true than the more specific assertion.

Modern usage

Many English speakers use "begs the question" to mean "raises the question," or "impels the question," and follow that phrase with the question raised,^[12] for example, "this year's deficit is half a trillion dollars, which begs the question: how are we ever going to balance the budget?" Many philosophers and grammarians deem such usage incorrect.^[13][14] Academic linguist Mark Liberman recommends avoiding the phrase entirely, noting that because of shifts in usage in both Latin and English over the centuries, the relationship of the literal expression to its intended meaning is unintelligible and therefore it is now "such a confusing way to say it that only a few pedants understand the phrase."^[15]

See also

Notes

References