I try not to know what just ain't so

Everyone must be familiar with the quote "It ain't so much the things we know that get us into trouble. It's the things we know that just ain't so". I once used it in something I was writing and being a pedant I went looking for the original author of the saying. Something in my mind said that it was Ralph Waldo Emerson, but something else said that it didn't really sound like Emerson. I knew it was an American, but it didn't sound like Walt Whitman, Edgar Allen Poe or T. S. Elliot either, so I checked. I found many attributions, and what all these attributions had in common was that the writer was absolutely sure that it had been said by Mark Twain. Or Josh Billings. Or Artemus Ward. Or Will Rogers. Or … .

Here was possibly the most famous saying in the world warning about being both sure and incorrect and the evidence was clear that at least some people talking about it were both sure and incorrect.

We all know stuff that is wrong, and the object of skepticism (and therefore its descendant, science) is to minimise the things we know which just ain't so. I suppose I could return to the extreme skepticism of René Descartes and accept that the only thing I can be sure of is my own existence, but I prefer to think that I can take some things on trust. As an example, I assume that when I email this article for publication there is an editor (whom I have never met) and a magazine to put it in. (Philosopher joke: I attended a solipsist conference once, but I knew the content of all the papers before I got there and all the girls in the bar looked like my wife.)

People can have beliefs and knowledge bases for three reasons, and I have called these "fact", "faith" and "fiction".

The first class is knowledge – people believe or know something for rational reasons based on the reality of the universe and on good evidence. I allow that second-hand evidence is almost always sufficient, provided that the method of gathering the evidence and the means of interpreting it by experts and authorities can be trusted. This is a recursive process – we can accept with some confidence information coming from sources that have been shown to be reliable in the past. Nobody can do all the research necessary to be personally assured of the truth about everything, so we rely on scientific journals and the news media to get things right for us. They do this most of the time, and failures and corrections are usually well publicised.

The second class contains religious, moral, aesthetic, or ethical beliefs. These may not (and perhaps should not) be logically or empirically justified, but their basis in faith must be recognised. Beliefs in this class may or may not have an observable effect. Liberalism is an example of an ethical belief which affects others, but, as Blaise Pascal pointed out, belief in God may have absolutely no effect in this life but an enormous effect in the next.

The third class is belief in nonsense, which has no effect on anything, and cannot be justified in any way. I was predestined to be a methodical, rational empiricist because I was born on the cusp of Virgo and Libra. Beliefs in this category can often be harmless and fun, but they can cease to be fun if taken seriously.

All of these belief classes are valid and most people have all three, although none are mandatory. People lacking beliefs in the third, nonsense, class can be extremely boring and humourless. People lacking religion, morals, and ethics are extremely unpleasant. Anyone without rational beliefs is probably mad. There is only a problem when the boundaries become distorted or overlap.

All this preamble is a way of saying that there is a qualitative difference between science (which is basically the first class), non-science, and nonsense. It is not sufficient, however, to simply show that such demarcation is possible. I believe that it is essential to actually make and use the distinction.

When people lose the ability to distinguish between fact and fiction they may also lose the power of rational thought, with consequent tragic results. There will always be charlatans who know the difference but pretend there is none, and there will always be cranks and crackpots who deny a difference because they cannot see one. It is the task of rational people to defend against both groups, and the only defence is a clear understanding that there is a real difference between science and non-science. They are different, and the difference is absolute. Some beliefs can be proved, some can not, and nothing can be both.

This article was published as the Naked Skeptic column in the July 2009 edition of Australasian Science