Because I Said So

This is the authoritarian or “Appeal to Authority” type of logical fallacy. When someone claims expertise on a subject and that someone makes a claim about a different subject, people automatically believe. The pattern looks like this:

1) Person A is (claims to be) an authority on subject S.

2) Person A makes claim C about subject S.

3) Therefore, C is true.

This is only a logical fallacy when the person in question is NOT an expert on subject S. I know…I know… It looks like a big algebra problem, doesn’t it?  Let me break it down into bite sized pieces.

Say that you know I’m a lab assistant at the CDC. I analyze tissue samples for a living so I know something about biology and infectious diseases. We’re at a party talking about the Large Hadron Collider. If I were to tell you that the Large Hadron Collider uses a form of lasers shot in a big circle to smash atoms, you might believe me because I am a scientist rather than investigate for yourself.

[[The Large Hadron Collider actually hurls protons at each other at 99.99999% the speed of light to create new particles. There is absolutely no danger of it creating a black hole. I’ll explain what it really does in more detail in another post]]

So here the logical fallacy comes in when we believe someone to be an authority figure on a subject based on the fact that they might be in a field that is generally related to the one they are claiming authority on just because they say they know.  And if THAT isn’t a run on sentence, I don’t know what is.

Let me try to make it even easier. In real life I’m a herbalist. I know quite a bit about the chemicals in herbs and how they work on the human body. If I were to say that penicillin molecules can penetrate the blood-brain barrier and you believed me without researching the truth for yourself (that is a false assertion by the way) then that is an example of this type of logical fallacy.

Even though I know a great deal about phytochemistry, ACTUAL chemistry involved in creating medicinal penicillin is still not something I know much about.

So, as usual I’ll suggest that you think critically. Ask yourself if this person is really an expert in that field. Do your own research. is a great place to start.


Newer entries »