Arguing from Authority

Jason Rosenhouse (EvolutionBlog) has blogged about the authority (or lack of it) of mathematicians commenting on evolutionary theory in a series of two posts. Start reading with the first one, Are Mathematicians Qualified to Discuss Evolution, Part One, and follow along from there.

The reason I’m calling attention to this particular entry is that many people struggle with the issue of authority, especially in regard to complex areas of study. I’ve found that in church work people often ridicule the authority of people with advanced degrees, while at the same time coveting, and actually giving too much authority to people with such degrees. The many diploma mills that hand out doctoral degrees, especially in the area of Bible study and theology demonstrate the desire to put “doctor” in front of one’s name, or to have a pastor for one’s church who does.

Rosenhouse makes an excellent and very clear statement:

But that doesn’t mean that a mathematician (or any non-biologist) is therefore forever excluded from discussing biology. It means simply that their professional training gives them no authority for doing so. Whether you should accord any weight to their pronouncements depends entirely on the specific arguments they make in defense of their views.

I think that statement is exceptionally clear, though some of the commenters seem to have ignored that point. My field is Biblical studies. I can comment all I want on evolution, and readers of this blog know that I do, but my comments need to be evaluated on the merits of the individual arguments. I hope that I get these comments right. None of them are original, and I can normally point you to the book by an appropriate expert, but I do lack authority in that field.

Ordinary people have to deal with this type of issue all the time. If experts are in disagreement, how do you make a determination? How do you find your way through the evidence?

One way, of course, is through authority. You find lists of people who support your particular position, and then you follow the crowd. And if you select people who actually are experts in that field, and find the consensus position of such experts, then you will likely not go too far wrong.

What’s interesting in the case of evolutionary theory is that we are presented constantly with lists of authorities, and it is the minority who are primarily making the argument from authority. Further, they often confuse the areas of expertise involved, as Rosenhouse notes in his post. Any number can be made to look impressive if you create a context designed entirely for that number. (Note here that I’m a non-expert commenting on mathematics, even in a very simple form.) We see this daily in advertising. A car is advertised at a “savings of $3,000.” Another is advertised at the “low, low price of $14,995.” What is the actual savings, or value, of each vehicle? Those numbers need to be placed in context. In the grocery store you have items for $0.50 off, “buy one, get one free,” “4 for $3.00,” “20% off,” and so forth. Those numbers aren’t selected randomly. The person doing the pricing uses the number that appears most impressive.

Thus the Discovery Institute can claim 600 scientists skeptical of evolution, but in order to evaluate that number, even assuming that one wants to use an argument from authority, one needs to know a number of things. What fields are these scientists qualified in? What percentage of the experts in that field does the number of signatories constitute? What precisely were they asked to indicate by their signature? Without those elements of context, the numbers themselves will be either meaningless or misleading.

So as a non-expert, what do I recommend? Well, my own approach, after growing up as a young earth creationist, was to start where I did have expertise, in Genesis 1-11 and archeology. I soon discovered that the young earth position was untenable even without considering geology. It may seem strange to evolutionists who started understanding geology, but I really had no concept of the age of the earth when I first rejected creationism. I simply knew that based on material on which I was qualified to comment, the young earth position must be wrong. All I said at the time was that the earth must be substantially older than 10,000 years.

Since I had read an abundance of creationist literature, I then started to read material from experts on evolution, emphasizing informational material. Roadside geology guides accompanied me on a number of trips in the west. As I would try to recognize formations, and would then compare what I saw with the guide, I quickly realized that this was not something I would become an expert on. So how did I evaluate it?

Here are the major points:

1. The real numbers-what is the expert consensus. For a non-expert to go against the consensus of experts should require a substantial body of evidence, generally gleaned from dissenting experts. For an expert, of course, what is needed is solid evidence and research.
2. What do they say about things I do know? If they comment on a topic on which I can comment with some authority, and do so incorrectly, then I begin to question the entire work. I recall reading a work on archeology by a mathematician. Within the first few pages I realized he was proposing calculations based on a level of accuracy of measurement that was simply not possible. For example, measuring something that is a hundred meters or so in length, and whose length includes an estimated portion (thickness of the covering of a wall when the covering no longer exists), and then using the resulting figure accurate to 4 decimal places is odd, at best!
3. How well do they represent the positions and arguments of opponents. I found that creationists in general did not decently restate the arguments of evolutionary scientists. In fact, the entire picture of evolutionary theory I learned while growing up was not an accurate representation of evolutionary theory. I tend to doubt the word of someone who misrepresents–intentionally or through ignorance–something that I can easily check.
4. Track back everything as close to the source as you can. There are practical limits based on the libraries available, how serious your interest is, and your knowledge of the field, but it is valuable to get as close to the person who found and cataloged the data. When the story changes as you get closer to the source, you know there’s a problem.

These are just a few suggestions.

One final note. For those who are interested in specifically avoiding mathematical deception, try one of the following: How to Lie with Statistics or Damned Lies and Statistics. Both will help you untangle the way in which numbers can be used to deceive you.