Argument from authority
|Look up auctoritas in Wiktionary, the free dictionary.|
Argument from authority (argumentum ad auctoritatem), also authoritative argument and appeal to authority, is an inductive reasoning argument that often takes the form of a statistical syllogism. Although certain classes of argument from authority can constitute strong inductive arguments, the appeal to authority is often applied fallaciously.
Fallacious examples of using the appeal include:
- cases where the authority is not a subject-matter expert
- cases where there is no consensus among experts in the subject matter
- any appeal to authority used in the context of deductive reasoning.
In the context of deductive arguments, the appeal to authority is an logical fallacy, though it can be properly used in the context of inductive reasoning. It is deductively fallacious because, while sound deductive arguments are necessarily true, authorities are not necessarily correct about judgments related to their field of expertise. Though reliable authorities are correct in judgments related to their area of expertise more often than laypersons, they can still come to the wrong judgments through error, bias or dishonesty. Thus, the appeal to authority is at best a probabilistic rather absolute argument for establishing facts.
|Look up ad verecundiam in Wiktionary, the free dictionary.|
The phrase argumentum ad verecundiam is sometimes used synonymously to mean 'argument from authority'. While it is linked, it does not have the same meaning. The Latin noun verecundia means "modesty" or "shame". Its link to arguments from authority is that they are used to make those who lack authority feel shame about discussing issues they lack credentials of expertise in, and modestly back out of an argument. The reason it is a fallacy is that the stature of the person to whom the remark is directed is precisely the open question under debate.
The argument from authority can take several forms. As a statistical syllogism, the argument has the following basic structure:
- Most of what authority A has to say on subject matter S is correct.
- A says P about subject matter S.
- Therefore, P is correct.
- The authority is a legitimate expert on the subject.
- There exists consensus among legitimate experts in the subject matter under discussion.
The two factors — legitimate expertise and expert consensus — can be incorporated to the structure of the statistical syllogism, in which case, the argument from authority can be structured thus:
- X holds that A is true.
- X is a legitimate expert on the subject matter.
- The consensus of subject-matter experts agrees with X.
- Therefore, there exists a presumption that A is true.
Fallacious arguments from authority often are the result of failing to meet at least one of the required two conditions (legitimate expertise and expert consensus) structurally required in the forms of a statistical syllogism. First, when the inference fails to meet the first condition (inexpert authority), it is an appeal to inappropriate authority, which occurs when an inference relies upon a person or a group without relevant expertise or knowledge of the subject matter under discussion.
Second, because the argument from authority is an inductive reasoning argument—wherein it is implied that the truth of the conclusion cannot be guaranteed by the truth of the premises—it also is fallacious to assert that the conclusion must be true. Such a determinative assertion is a logical non sequitur, because, although the inductive argument might have merit—either probabilistic or statistical—the conclusion does not follow unconditionally, in the sense of being logically necessary.
See also 
- Salmon, M. H. (2006). Introduction to Critical Reasoning. Mason, OH: Thomson Wadsworth. pp. 118–9.
- Gensler, Harry J. (2003). Introduction to Logic. New York, NY: Routedge. pp. 333–4.
- Baronett, Stan (2008). Logic. Upper Saddle River, NJ: Pearson Prentice Hall. p. 304.
- See generally Irving M. Copi, Introduction to Logic, Macmillan Publishing Company (7th ed. 1986), pp. 98-99.
- Marguerite H. Foster, Michael L. Martin (eds) Probability, Confirmation, and Simplicity: Readings in the Philosophy of Inductive Logic Pub. Odyssey Press 1966
- Peirce, C. S. et al., Studies in Logic by members of the Johns Hopkins University (1883)
Salmon, M. H. (2006). Introduction to Logic and Critical Thinking. Mason, OH: Thomson Wadsworth. pp. 118–9.