Ockham’s Razor and the Spooks

Anyone who knows me well knows that I hate many, many things.  In a time when atheists are fighting desperately to be seen as good, kind, well-meaning folk, I brazenly admit to being an angry, pissed-off atheist.  But of all the things that anger me—whether it be God, religious fundamentalists, chiropractors, naturopaths, conspiracy theorists, or recently-pregnant women who won’t stop talking about their damned kid—few things piss me off more than people who misuse and misunderstand the concept of Ockham’s razor.  Mary Roach, the well-known pop-science author of books like Spook, Stiff, and Bonk, is the latest to anger me in such a manner.

In her book Spook: Science Tackles the Afterlife, Roach portrays herself as a sort of wishy-washy, noncommital skeptic.  This, too, is the sort of thing that angers me, as one should always devote one’s life fully to skeptical principles with flair and gusto.  However, when she totally abuses the principle of Ockham’s razor, defiling it with her innocent, questioning prose, I couldn’t help but look at Spook with a sort of enraged pity, not unlike the way one looks upon a mangy dog that has suddenly began humping a small child; it is a disgusting, wretched display, but we almost forgive it because it is too stupid to know any better.  Indeed, I almost feel saddened to have to eviscerate Roach’s well-meaning, but horribly incorrect, description of Ockham’s razor.  But it must be done, for the sake of edifying my readers and delighting myself.

For a little context, Spook essentially details the long history of pseudoscience concerning the afterlife and ghosts.  She investigates soul-weighing experiments, crackpot physical theories about the survival of consciousness after death, and so on.  For me, it was a light, fun read until I finally read her description of Ockham’s razor, which caused me to have a raging seizure and dress my dog up as an effigy of her book while beating it relentlessly.  She explains the principle in a chapter about the capacity for infrasound (low-frequency and inaudible sound waves) to induce paranormal experiences, like sensations of a felt presence.  She ends the chapter like so:

If you ask me which is the more likely explanation—infrasonics or spirits—I will tell you to apply the wisdom of Occam’s razor, a principle which holds that the simplest, the least far-fetched, of two competing theories is the place to put your money. But depending on who’s shaving, Occam’s razor yields manifestly different views. To those who believe in an afterlife, the most straightforward explanation for hearing your dead dad is that you’re hearing your dead dad’s spirit. Infrasonics and vibrating eyeballs and fight-or-flight responses would, given this particular worldview, seem to be needless and unlikely complexities (p. 237).

You can't use Ockham's razor on just anything, especially suicide attempts.

Mary Roach’s understanding of Ockham’s razor is distressingly common.  Few people understand what the principle actually entails, largely owing to an unfortunate and misleading sound-byte interpretation frequently rendered as, “The simplest explanation is the best.”  Of course, worded like that, the principle is indeed stupid and ambiguous and should be pelted with baboon feces.  After all, if mere simplicity provides the royal road to truth, then that crazy, complicated science stuff, which is inundated with complex equations and statistics, goes right out the window in favor of the Ken Ham/religious mystic view of reality, complete with men riding atop saddled dinosaurs and the Earth resting upon an infinite series of stacked tortoises.  Truly, if the simplest explanation really were the best, then this overly simplistic paraphrasing of Ockham’s razor would suffice.  Unfortunately, Ockham’s razor doesn’t rely only a vague, amorphous conception of simplicity; instead it relies on a very precise and complex definition of exactly what makes one theory more epistemologically complex than another.

Roach goes wrong in just this way, by assuming an ambiguous definition of Ockham’s razor in terms of whether a theory is “simple” or “far-fetched”.  The principle is best explained in its more complex, fleshed-out form (as opposed to the walking-dead zombie form used by Roach) to avoid such confusions.  Basically Ockham’s razor states that the theory that makes the fewest assumptions, given the current state of evidence, is the best theory.  In essence, the principle only demands that the claims of a theory be founded in some sort of evidence or fact, as those theories that proliferate in hypothesized, assumed entities for which there is no evidence are less likely to be true.  For instance, if I explain the water cycle with stages of precipitation and evaporation, this water cycle theory is more parsimonious than a hypothesis that posits a water cycle model with the stages of precipitation, evaporation, and magical elves.  The latter model would be rejected by Ockham’s razor because it posits magical elves when there is no additional evidence in support of their existence, and because the model that posits only precipitation and evaporation adequately models the water cycle without positing any elves or magic.  In a nut shell, Ockham’s razor tends to lead to truth because it prohibits baseless assumptions, and as we all know it is much easier to be incorrect when we come to conclusions based on assumptions for which we have no evidence.  If you want to add magical elves to your theory, find evidence of magical elves.  It’s really quite simple.

Now let’s apply Ockham’s razor to competing explanations concerning sensations of ghostly presences, as in the example from Spook quoted above.  One hypothesis posits that known entities like low-frequency sound waves and flight-or-fight stress responses can produce these sensations, with a smattering of evidence to support the claims.  The other hypothesis posits that actual ghosts are producing these sensations, with no evidence of ghosts other than these disputed sensations.  According to Roach, Ockham’s razor cannot decide between these two hypotheses, because one’s worldview—depending on whether it accepts the supernatural or not—would influence what one considers the “simpler” theory.  But this is not a correct application of the principle, as Ockham’s razor is decidedly not ambiguous with a proper contextual definition of the word simple.  The first hypothesis posits entities that everyone agrees already exists; we have plenty of evidence demonstrating that low-frequency sound waves and flight-or-fight responses are present in reality.  The other hypothesis, however, invents a new existential entity, and further a new existential category (the supernatural), in an attempt to explain the evidence, even in spite of the fact that there is no other confirmation of the existence of such paranormal entities.  Now, if we can explain the phenomenon with already-existing entities like sound waves, there is no further need to posit anything more, much less an entirely separate and ineffable spiritual plane of reality.  The paranormal claims are thoroughly shaved away by Ockham’s razor, regardless of your worldview, because the principle depends only on reality and evidence, not ideology!

So just as we reject magic elves as necessary to explain the water cycle because already-known processes like evaporation and precipitation can explain the cycle, so too are we led to reject paranormal hypotheses concerning strange sensations of vague presences when already-known processes can account for the evidence.  Ockham’s razor, far from being a tool that can be wielded haphazardly by two sides of a dispute to come to startlingly different conclusions, actually slices open paranormal claims and reveals them for the empty, silly nonsense they are.  Like any good razor, Ockham’s razor only has one handle, and it can only be grasped from that one side.  Anyone who tries to grab it from the other end only winds up getting sliced.