An appeal to authority, argument from authority or argumentum ad verecundiam is one method of obtaining propositional knowledge. Some examples of appeals to authority:
- Referring to the philosophical beliefs of Aristotle.
- Quotes from religious books such as the Bible.
- Claiming that some crime is morally wrong because it is illegal.
- Referencing scientific research published in a peer reviewed journal.
- Believing what one is told by one's teacher.
Citing a person who is a recognized authority in the field is likely to carry more weight. In the middle ages, roughly from the 12th century to the 15th century, the philosophy of Aristotle became firmly established dogma, and referring to the beliefs of Aristotle was an important part of many debates. Aristotle's thought became so central to the philosophy of the late Middle Ages that he became known in Latin as Ille Philosophus, "the philosopher," and quotations from Aristotle became known as ipse dixits ("He, himself, has spoken.").
Authoritarian ethics is the ethical theory by which one attains ethical knowledge from an authority, for example from a God or from the law. The bandwagon fallacy can be viewed as a special case of an appeal to authority, where the authority is public opinion.