Appeal to Authority

Also known as Appeal to: Irrelevant Authority, Questionable Authority, Inappropriate Authority, Argumentum ad Verecundiam.

24th July 2014

An Appeal to Authority is where someone puts forward an argument and invokes some entity's conclusion, relying on its authoritative position or status, to support it rather than providing their own reasoning or evidence. Such an entity could be a group, person, organisation, scripture, etc.

The basic structure is:

Strong sense:

  1. An authority has stated that X is true; therefore
  2. X is true.

or Weak sense:

  1. An authority has stated that X is true; therefore
  2. X is probably true.

When used in a strong sense, an Appeal to Authority is always fallacious. This is because there's no guarantee that an authority will be correct. In short, even experts can be wrong.

The Appeal to Authority is normally used in a weaker sense in support of a claim; and when used this way, its quality can vary from being perfectly reasonable to completely untenable.

In order to evaluate the strength of an Appeal to Authority, several aspects need to be addressed.

  1. Who or what is the authoritative source of information?

    Is the person, organization, or source being referenced really an authoritative source? It is important to distinguish between an authority and a perceived authority as the degree to which an authoritative source can be used to support a claim depends crucially on their actual authoritative status.

    In academic fields, experts will normally be relevantly qualified, have published papers, be recognized by their peers, etc., which means their status can be gauged reasonably easily and accurately. In other areas, such as in the humanities, sport or the “soft sciences”, what constitutes an expert can be harder to establish.

    The authority should also be identified, otherwise the fallacy of “Appeal to Unidentified Authority” occurs. Phrases such as: “scientists agree that...”, “I read a book which said...”, “I heard an expert say...” and similar are not legitimate Appeals to Authority.

  2. Is the source qualified in the relevant area?

    It is not sufficient for a source simply to be an authority when used to support a claim; the authority also needs to be an expert in the relevant area. An expert who is commenting on something outside their area of expertise will provide a reduced, perhaps insufficient, level of support for the claim.

    Expertise in one area does not mean that someone is an expert in unrelated areas. For example, a world renowned physicist should not automatically be afforded the status of expert when talking about child rearing practices – even if she's a mother herself.

    There are also topics where it's hard to decide what it means to be an expert. Can someone be an expert in astrology, for example? It may be possible to be an expert about astrology but is it possible to discern whether one astrologer's ideas on astrology are any better than any other astrologer’s?

  3. Is the source impartial in respect of the claim?

    Although a relevant authoritative source may have been cited to support a claim, it is important to ascertain whether the source is biased in some way which influenced its conclusion rather than it being based on reason or evidence alone.

    Everyone has their own biases: prior beliefs, world-view, cultural or religious background, etc., which influence them, so no person is ever free from bias. Even in science, especially the soft sciences, evidence is evaluated and this means that personal biases can creep in. It's the degree to which biases can influence conclusions that needs to be assessed – not just the presence of biases per se.

    Examples: an obstetrician may express anti-abortion views. If they are also a strict, practising Catholic, their religious beliefs may have more to do with their conclusion than the science or other aspects of the issue – thus weakening their status as an impartial authority. Or, a dentist may recommend a certain brand of toothpaste, but if they're being paid to advertise it by the manufacturer, their impartiality has to be doubted.

  4. Do other similarly relevant experts hold the same conclusion?

    An individual authority's conclusion on an issue will not be sufficient to support a claim on its own. For an expert's conclusion to be strongly supportive of a claim, their conclusion must also be held by the vast majority of their peers. This is because some relevantly qualified experts hold views that are in complete contrast to the consensus view in their field – which means they are unlikely to be right.

    This is usually clear-cut with scientific issues; however, there are other areas where there's much disagreement even between the experts in the field. Political debates, e.g. how to tackle a budget deficit, often result in experts proposing completely different, often contradictory, solutions to the same problem. In this scenario, any appeal to an authority in support of a conclusion is going to be very weak – as counter-Appeals to Authority will be of equal strength.

    This issue of consensus is not about whether any particular expert is right or wrong, but how their position within their field affects their strength as an authority. The easier their conclusion is to challenge, the weaker their status as an authority is in support of an argument.

Is an Appeal to Authority always fallacious?

Formally, or deductively, yes.

However, an Appeal to Authority is normally used inductively, or informally, and so the issue surrounding its usage is the level of support it gives to a claim – i.e. does it strongly or weakly support the claim?

If the criteria stated above are matched then the authority's position will strongly support the claim; but if the criteria, one or more, are not matched then the level of support for a claim is weaker or even non-existent.

Some issues are very complex and beyond the expertise of the individual trying to assess them. In such instances, it is reasonable to appeal to an authority's position on the matter as long as it's a reliable, recognized, impartial and accepted authority.

Examples of weak Appeals to Authority:

  1. Homeopathy does work. After all, Prince Charles believes in it and uses it himself!

  2. Smacking children is wrong and should be banned. The biologist professor Alice Bloggs has stated so.

  3. Telepathy is real. I agree with Nobel Prize winning physicist professor Brian Josephson who said: "there is a lot of evidence to support the existence of telepathy"[1].

In the first example, Prince Charles may very well have a strong opinion on homeopathy. The fallacy with citing him, however, is that he's not a relevant authority on medical matters. It's only because of his esteemed position that his opinion is assumed to carry more weight. We have a tendency to listen to authority figures (perceived authorities) so this fallacious argument is put forward frequently. It is often used in advertising as the "celebrity endorsement" of a product.

In the second example, professor Bloggs is a biologist and not a child psychologist or relevant expert in the field. The fact that she is highly qualified in one area does not mean that she's therefore an expert in all areas.

In the third example, Josephson is a Nobel Prize winning physicist. As a physicist who studies the paranormal from a physicist's point of view, he may be deemed to be a relevant authority too. However, how many other physicists would agree with his conclusion? NOTE: it's his status as a Nobel Prize winning physicist that greatly enhances his authoritative status.


Formally, an Appeal to Authority is always fallacious. However, such arguments cannot always be dismissed because in many instances, an appeal to (a relevant, reliable) authority can be a good, reasonable argument – it's often the only position a non-expert can take.

The strength of an Appeal to Authority's support for a claim needs to be assessed. Fortunately there are criteria available which can help to decide whether the appeal is pertinent.


  1. The Guardian

NOTE: There is a special case of the Appeal to Authority. This is in the instance of self-proclamation. Here the authority quoted is the person themselves (known as ipse dixit).