Friday, June 7, 2013

[PL 211] Ockham's Broom and Appeals to Expertise

In this Science Weekly podcast (starting from 21:38), Daniel Dennett talks about his book, Intuition Pumps and Other Tools for Thinking. At one point, Dennett mentions "Ockham's Broom." Coined by Sydney Brenner, the term refers to sweeping under the carpet inconvenient facts (i.e., facts the undermine the claim one argues for).

The problem is that, as Dennett says, only experts can identify when Ockham's Broom has been used. Novices or non-experts will not be able to tell that inconvenient facts are missing from an argument for or against a certain claim.

If that is the case, however, then should novices rely epistemically on experts? That is, if non-experts cannot tell when an expert is using Ockham's Broom in order to make an argument look more convincing than it actually is, how much trust (if at all) should they put in what the expert says?


  1. An expert is a person who has a comprehensive and authoritative knowledge or skill in a particular area, a specialist. Daniel Dennet, a philosopher, discusses the innocent use of the concept of Ockham’s Broom as the sweeping of inconvenient facts under the rug when they do not favor their view in an argument, such as when a scientist forgets to mention a study in the heat of the battle, which does not favor his view. However there are times when it is used to intentional mislead those with only common knowledge on a subject. People need to be able to reach their own decisions on topics and not just be guided by experts. Even Dennet, who is a philosopher, an expert in philosophy, has “learned to be cautious about simply taking at face value things taught by people in their published papers”… it is not until he “goes to the lab to see circumstances that he will suddenly see what the set up was”. It is the same with non-experts relying on what the experts says, it is assumed that we know the things that go without saying with their interpretations, we need to have some background information and knowledge in order to evaluate what they are saying so we will have a modified view of what is going on. As the video, The Trouble with Experts demonstrated, not all experts’ opinions can be trusted, they too are subject to persuasion, and after all they are only human. But if the opinion one gets from the expert is a satisfying result, what does it matter if it is without flaw. If it is something that will cost you a great deal of time, money or our health, I believe you need to get all the information you can and make an educated decision on your own, not relying solely on what someone else tells you, whether they are an expert or not.

  2. The term “Ockham’s Broom” does create a sense of doubt when accepting the findings of an expert. However, I do not believe it completely diminishes the credibility of the expert. In order to fully accept an expert it is our duty to do our own research in order to validate the argument. One way is to read the reviews of others experts in that field to see if they mention any important facts that have been left out. If sufficient reviews indicate that the expert doesn’t use Ockham’s Broom, then the findings may be trusted without doubt. However, relying undoubtedly on an expert isn’t wise. It is naive to believe that everything an expert says is true.

    Mehrun Uddin

  3. I think, as Dennet said during the interview, it's important to do research and get several expert's opinions to have a better grasp on the situation. If a non-expert jumps into a situation blindly relying on the expert's opinion, the non-expert may receive different results than expected. Of course, we can't immediately distrust all experts, but it is possible to be cautious about what we believe to be true.

    For example, there's a documentary called Burzynski about a doctor who supposedly found a cure to certain cancers, but he was not approved by the FDA. The movie depicts him as a hero, fighting against the corrupt government in order to save patients' lives. The patients had to pay full price for the treatment (which was very expensive) because it was not approved. As the documentary went on, I kept asking myself WHY doesn't the FDA approve of this method. I did a bit more research and I discovered that, while Burzynski seemed to have kept meticulous data in the documentary, his presentations to get the FDA to approve his research left out information. So, even though the documentary focuses on an expert, it seems that the documentary makes use of "Ockham's Broom" in order to depict Burzynski in a particular way. If a non-expert (like myself) watched this movie but did NOT do some more research, he or she may have completely bought into this treatment (which may not be as effective as depicted in the film).

    Like I said, I think it's important to trust experts to an extent. For most fields, there are so many experts that it's probably better to get a few different perspectives. With patients suffering with diseases should go to a few different opinions to get a full picture of the disease and treatment options. If you're interested in buying one of those weight-loss products, why not look at different experts' opinions? It's always good to research and learn everything you can about a particular situation before you invest yourself in one option/belief. Your thinking becomes more critical, your knowledge becomes more well-rounded, and you begin to get a better understanding of what is going on around you. What is the harm in that?

  4. In my opinion, novices should not rely epistemically on experts. In most cases, experts are able to give professional advice on particular areas. However, as mentioned in this article, sometimes experts would use Ockham's Broom in order to make their arguments more convincing. Also sometimes experts may use this theory for their own benefit like reputation. Thus novices should choose to believe experts’ statement based on their own knowledge. They should try to understand the elements of argument by themselves through their own ways like internet. When they are unenlightened, they can only believe what the experts tell them. After they have a basic knowledge about the argument, they can use their own judgment to believe what is true and what is not. How much trust they should put in experts depends on how much knowledge they have. In other word, the more knowledge they have, the less trust they could choose to put in experts.


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