Invincible authority

Invincible authority is a fallacy that occurs when an authority's opinion on an idea is cited as if that authority's support was the only evidence necessary to uphold said idea.

The fallacy is an appeal to authority and thus a conditional fallacy.

Examples

 * Einstein believed in a god, so I'm going to.
 * The world was created in seven days, because the Bible says so.
 * [Famous Person X] uses [Product Y]; so will I.
 * Aristotle held that some men were fit only to be slaves, therefore slavery is justified.
 * Many Christians make a special case for the Bible / God / Jesus, arguing that everything else can be questioned except God. Often, this relies on the circular reasoning that God inspired the Bible because the Bible says so.

Problems
Such an argument is fallacious because there is no given reason why the authority's word should be accepted as final. The fallacy also faces the issue that only the authority's opinion is considered, while no opposing arguments are.

The line between invincible authority and a valid argument from authority can be difficult to draw; this does not mean no distinction exists. A sound argument based on citing authorities requires:
 * 1) supporting the authority of the authority (e.g., the authority is an expert in the field, has been widely published, and agrees with scientific consensus) and
 * 2) hedging your bets (because even the most qualified authorities make mistakes) and asserting that the authority's support merely makes an argument likely true, not necessarily true.

Ultimately, however, this fallacy underscores the weakness of citing authorities instead of arguments.