Begging the question

In classical rhetoric and logic, begging the question or assuming the conclusion (Latin: petītiō principiī) is an informal fallacy that occurs when an argument's premises assume the truth of the conclusion. Historically, begging the question refers to a fault in a dialectical argument in which the speaker assumes some premise that has not been demonstrated to be true. In modern usage, it has come to refer to an argument in which the premises assume the conclusion without supporting it. This makes it an example of circular reasoning.^[1][2]

Some examples are:

• “Wool sweaters are better than nylon jackets as fall attire because wool sweaters have higher wool content".^[3]
  • The claim in this quote is that wool sweaters are better than nylon jackets as fall attire. However, the justification of this claim begs the question because it presupposes that wool sweaters are better than nylon jackets: in other words, wool sweaters are better than nylon jackets because wool is better than nylon. An essentialist analysis of this claim observes that anything made of wool intrinsically has more "wool content" than that which is not made of wool, giving this quote weak explanatory power as to why wool is superior to nylon in the first place.
• "Drugs are illegal so they must be bad for you. Therefore, we ought not legalize drugs because drugs are bad for you."^[4]

The phrase beg the question can also mean "strongly prompt the question", a usage that is distinct from the sense in logic but is widespread,^[5][6][7][8] though some consider it incorrect.^[9]