The Green Troll in a Red Dress

The Green Troll in a Red Dress

When you are confronted with a weird idea, it is important to keep in mind a simple statement popularized by the late astronomer Carl Sagan, "Extraordinary claims demand extraordinary evidence." Remembering this when it counts can save you time, money, embarrassment, and possibly even your life. There is great power in these five words, enough to slay dragons and repel the crooks and crazies.

To put it into action, the first thing we need to do is to assess the size of the claim so that we can assess the amount of evidence that we need to accept it. No, put away the scales and tape measure. A general estimate is all that is needed. For this, "a little" or "a lot" are fine units of measure in most cases. It's about seeking a rough balance, that's all. We don't demand mountains of evidence for every claim anyone makes about anything, of course. That would be overkill and would waste too much time. For example, if for no particular reason I tell you that I saw a blue car driving on the road near my house yesterday, you would be right to go ahead and believe me. Seeing a blue car is not an extraordinary claim. There are millions of blue cars. It's reasonable and likely to be true that I saw one. And so what if I did? It's not a big deal. It's not like I'm asking you to attend my weekly blue-car-sighting meetings and make a monetary donation on behalf of the blue-car fund of America. You can probably go ahead and trust me on this one. But what if I make a very different claim? What if I say that yesterday I saw a winged troll with green skin wearing a spectacular red dress and playing "God Bless America" on a jewel-encrusted harmonica while flying around in my backyard? Are you going to accept my claim and believe it happened? What if I also tell you that this particular troll is short on cash and needs $100 per week—which I have been authorized to collect for him? I hope that you wouldn't trust this story without more effort to prove its veracity on my part. It's an extraordinary claim, so it demands extraordinary evidence, right?

You don't have to disprove the troll story. That might be impossible. We don't know with absolute certainty that winged, green-skinned trolls do not exist. Maybe they do, and if they do exist, we don't know that they don't need money. We can't even say for sure whether or not they look great dressed in red. But that's okay. Doubt is enough. Being a good skeptic doesn't mean you have to know everything. It certainly doesn't mean you have to disprove every claim believers make.

The burden of proof is on me for making the claim in the first place. For a whopper of a tale like this one, I should have to produce tons of very good evidence if I want sensible people to believe me. Sadly, of course, if I wanted to and was willing to work at it a bit, I have no doubt that I could find a few weak skeptics somewhere who would believe in my green troll wearing the hot dress—no evidence required. Do you doubt it?