Many of you were too busy trying to ace organic chemistry to know what a deus ex machina is. For those of you who managed to squeeze in a classics course, please stick with me anyway.
Deus ex machina (“god from the machine”) is a literary device. In ancient Greek literature, a complicated dilemma was sometimes solved by having one of the gods literally pluck the unfortunate protagonist off the stage from the arm of a crane. It’s sort the ancient version of the Superman gambit—don’t like the ending? Just turn back time by reversing the rotation of the Earth. In either scenario, an impossible dilemma is circumvented by an improbable escape.
I bring this up because the machina is also used in debates. A valid logical argument (OK, philosophers, please hold your horses…this is the 101 course) requires true premises and a conclusion that must follow. For example:
All humans are mortal
I am human
Therefore, I am mortal
The premises are very likely to be true, and the argument as constructed is valid. The conclusion is very likely true.
Mercury is toxic
Vaccines contain mercury
Therefore, vaccines are toxic
This argument is a properly constructed, superficially valid syllogism. If the premises are true, the conclusion is true.
But the premises are not true. Mercury is toxic—sort of, some of the time, in certain forms, in certain doses, delivered in certain ways.
Most vaccines no longer contain mercury.
Since the premises are invalid, the conclusions are false, despite a seemingly valid argument structure.
(Hmm, I didn’t expect this post to go in this direction. Oh, well.)
Back to the machine. When debating various types of denialists, we skeptics are confronted with a problem. Whenever we present an argument that is valid and true, and the denialist can’t seem to wiggle out of it–BOOM!–cue the pyrotechnics, and wheel in the machina. The most potent of these machines is the conspiracy theory, because they are always presented as unfalsifiable arguments, that is, not matter what you say, the denialist can respond, “Yeah, but the CONSPIRACY MANIPULATED THE FACTS!!11!”
Once a conspiracy is invoked, the argument is over, and the denialist has lost (Pal’s Law?). A deus ex machina is the “nuclear option”—the validity of the argument is destroyed by rendering the premises unfalsifiable, unquestionable, and unassailable.
But rendering the premises immune from testing does not increase their veracity. In fact, it makes their veracity moot. Like any other argument, a conspiracy theory, and every other conversational machina have real, verifiable data to support it. My SciBling MarkH has often repeated, “Don’t debate denialists” and I’m with him for the most part. The debate is useful when it hinges on facts. But once they role in the machine, it’s time to pick up your toys and go home.