As a guest on a recent radio program, I took calls from people who’d had some ghostly experience. It’s not true that such callers are always trying to challenge the evil skeptic: “I saw my grandfather’s ghost at the foot of my bed, explain that, Mr. Skeptic!” In this case, most of the callers (I think) were genuinely hoping for some insight. Although I certainly couldn’t speculate about what their experiences might have been, I was at least able to avoid making some common mistakes that often cost skeptics their credibility.

First, you’re not going to convince a ghost believer by saying “We have no evidence that ghosts exist, nor is there any plausible hypothesis by which they might exist.” No ghost believer in history has ever heard that, said “Aaahh,” smacked themselves in the forehead, turned over a new leaf, and gone forth with a new perspective on reality. Logically, you have just as much evidence that ghosts don’t exist as they have that ghosts do exist. So it’s a weak argument. Thus, no good can come from starting off by contradicting their belief. The only thing it accomplishes is to establish an antagonistic tone.

Presumably, if they’re comfortable with a belief in ghosts, they’re also comfortable with a belief in other types of supernatural beings. Most people are religious, so this opens up the door of plausibility to angels and demons. Most people have some belief in psychic powers at some level, so this permits the introduction of mind projections, telepathy, and so on.

We always want to look for common ground, rather than for points of conflict. One thing that nearly everyone can agree upon is that none of the above phenomenon have any scientifically established known properties. There is no accepted, established body temperature for demons. There is no firm set of proven behaviors for a ghost. We cannot capture an astrally traveling being, perform a blood test, and prove that it’s an astral traveler. No supernatural being has a single known, accepted, concrete property. Most believers probably have their own general idea of what a ghost might look like and do, but everyone will acknowledge that different witnesses report different experiences.

So when someone expresses their belief that something they saw was a ghost, it’s perfectly reasonable to ask how they were able to rule out other possibilities. If you saw the apparition of your grandfather standing at the foot of your bed, how were you able to identify it as your grandfather’s ghost, rather than a demon trying to trick you? A psychic somewhere putting that vision into your head? Vibrational energy from your grandfather persisting around some of his belongings? A projection from your own subconsciousness? An angel of a yet-to-be-born person, using some image from your mind as a way to manifest itself? We don’t know what properties any of these things might have, thus there’s no way you can logically compare the details of your experience to them to determine what it was you saw. The spirit of your grandfather might be the most emotionally comforting option, but it might be important to find out if a demon is trying to trick you; so the mind should be open to that possibility too.

The more intelligent someone is, the more likely they may be to intellectually realize that there are other possibilities. A person who acknowledges that they do not know the cause of their experience is closer to the truth than a person who insists upon one specific, unsupportable conclusion.

Of course, this same logic applies to those who see something in the sky and identify it as an alien spacecraft. Consider the other possibilities: A vehicle from an unknown population of beings who live at the bottom of the ocean, or a craft from a subterranean race. Those are two possibilities that don’t require the assumption of the problems of interstellar travel having been solved. Perhaps the Earth even has its own race of beings who live in the sky, possessing all kinds of unfathomable aeronautical secrets. What would be the properties of one of their vehicles, and what would be the properties of an extraterrestrial spacecraft? How were you able to match up your observation to one, and to exclude the other? You can’t, since neither has any known properties; and so the only right answer is “I don’t know what it was.”

Notably, at no time have I advocated telling the person that they’re wrong, or that they misinterpreted what they saw, or that they imagined anything. Maybe that’s what happened, but I wouldn’t have any way to know that. I expect that in nearly every honestly reported case, the person did see something, even if was something mundane that for some reason manifested itself in a spectacular way. I find that introducing the suggestion that they were wrong or imagined something simply causes antagonism, and rarely leads to enlightenment.

One need not abandon one’s belief in ghosts or UFOs to take an important step on the journey to critical thinking. If a person can acknowledge, for the first time, that “I don’t know, therefore I know” fails the test of logic, they’ve improved their ability to interpret our world. Imagining what they’ll learn next is an exciting prospect indeed.