The purpose behind this post is to explain the difference between two things that pseudo-scientists often confuse: The logical fallacy of “Argument from Authority” versus the concept of a Scientific Consensus.
“Argument from Authority” is effectively the idea that Person A is a supposed authority in Subject B. Therefore, anything that Person A states about Subject B is true. For example, I could make the claim that Dr. Crusher is an expert on human anatomy. The fallacy then goes that if I were to say to my friends that Dr. Crusher says the neck bone is connected to the foot bone, then it must be true because she’s an expert in that field. But, obviously this is not true. In other words, the validity of the claim does not follow from the credibility of the source.
Less contrived examples of this are in some of the creationism and intelligent design posts that I have made. In them, the interviewer often states that their information comes from Dr. So-and-so, a scientist. This is the argument from authority, though, for any individual scientist is fully capable of self-deceit or deceiving others.
When I debunk these claims on this blog, I try not to use argument from authority for that basic reason. What I use is the general scientific consensus about what are the facts or general understanding of the subject at-hand. For example, the existence of the Kuiper Belt and Oort Clouds are accepted by the majority of astronomers — they have reached a consensus. A scientific consensus represents the most likely explanation given everything that we know at the time.
This, too, may sound like an argument from authority, but it is not. That is because the reason the argument from authority is a fallacy is that it is based on an individual‘s credibility. That is why science is supposed to be peer-reviewed – so that you can convince your colleagues of the claim’s validity based upon the scientific evidence. If the evidence is not real, sufficient enough, and/or can’t be replicated, then your claim will fall by the wayside and not be accepted by the scientific community. It is only after the claim has been vetted and accepted by the majority of scientists that it becomes a consensus opinion and hence not subject to the logical fallacy of argument from authority.
An example of this in modern science is the global warming “controversy.” The majority of climate scientists and modelers agree that global warming is in fact occurring and will continue to happen. This is the scientific consensus. However, there are still several scientists who disavow this viewpoint. If a news article were to just quote one of those scientists to say that there is still a scientific controversy over whether or not global warming is occurring, then they have just committed the argument from authority fallacy. The consensus is that it IS happening, and the debate over whether global warming is “real” or not is pretty much over.