“Occam’s Razor” is a powerful idea, but it is easily abused, misinterpreted and misunderstood. So let’s take a moment to discuss what we mean by Occam’s Razor in the context of the Occam’s Razor Investigation Society.

Occam’s Razor is related to simplicity, but not simplicity for its own sake. As much as I enjoyed Kevin Cook knocking the wind out of the Nazi UFO Ring investigation, he went astray when he said Occam’s razor states that “the simplest answer is always the best.” Sometimes the simplest answer is flat out wrong.

For example, say I wake up with chills, aches, fever and nausea. Which explanation is simpler: that the lady who gave me dirty look at the bus stop last week is a witch and cursed me, or that tiny biological machines called viruses are hijacking the invisibly small cells that make up my body, and my symptoms are a side effect of that struggle? The witch thing sounds a lot simpler to me. And it would definitely have seemed simpler to someone six hundred years ago with no knowledge of molecular biology. But simple or not the witch explanation is wrong, and it was just as wrong in 1410 as it is today.

Our modern understanding of germs and viruses and their role in disease came not just from looking for simple explanations. They came from the search for evidence, challenging old ideas based on that evidence, and the steady march of science toward the most consistent and useful explanation for the body of evidence that we gather. Most of us reject the witchcraft theory of disease because there is little evidence for witchcraft, there is significant evidence for the germ theory of disease, and more lives have been saved by treatments based on the germ theory than by treatments based on the witchcraft theory.

So what good is Occam’s Razor if you can’t just find the simplest explanation for something and declare the job done?

Science is not a body of knowledge. It is is not a set of facts you can bind in a book or display in a museum. Science is a method for investigating the world. It is a process. And Occam’s Razor is a statement of useful advice about how to go about that process.

The Latin phrase in the seal of the Society is one widely accepted statement of Occam’s Razor: “entia non sunt multiplicanda praeter necessitatem.” This can translate to “entities must not be multiplied beyond necessity.”

So what does this mean? It means that when developing an argument or an explanation, you should avoid explanations that require you to assume things that are not proven. If an explanation requires you to accept half a dozen things without good evidence, it’s probably not as good as an explanation as something that does not require so may assumptions. And if your best explanation requires only one or two assumptions beyond the evidence, and you can think of a valid way to test those assumptions — then you’re doing science.

In practice, of course, Occam’s Razor leads to something a little bit closer to Kevin Cook’s statement. When comparing two possible explanations for some phenomenon, there’s a very good chance the simpler explanation will be the more accurate one.

This places a responsibility upon all investigators. If you really want to explain something, you must at least consider the simplest, most mundane explanation first. More often than not it will be the best explanation, or will lead you there. Only when there is a good reason to reject the simplest  explanation should you move on to more complex possibilities. If you’re going to suggest an explanation that requires one to assume the existence of ghosts, demons or alien visitors, you’d better have some damn good reasons to reject more scientifically supportable possibilities — and some good ideas about how to prove the existence of these paranormal entities rather than just assuming that they are real.

The laughable thing about most UFO and paranormal TV shows is that they dive immediately to the supernatural and the speculative, and then act as if that’s a perfectly reasonable way to run an investigation.

Personally I’d be delighted by evidence of ghosts or aliens, but anyone who wants to convince me that they are real has a lot of work to do.