One of my favorite stories from the Roman era is that of the arrogant and quite unlucky (if you’re not superstitious) Publius Claudius Pulcher, a Roman consul who fought in the First Punic War. Pulcher set out with a fleet of ships to try to surprise the Carthaginian admiral and his fleet at Drepranum. Although Pulcher did gain the advantage of surprise, his inadequate leadership left the fleet trapped in the harbor, and it suffered the worst naval defeat in that war, losing at least 93 ships. The surviving ships ended up shipwrecked, and Pulcher was later tried for incompetence and heavily fined.
Historians and naval battle experts could toil for years over what went wrong with what should have been an easy Roman victory. However, there’s no need. We already have all the answers, and, of course, they’re the same answers to all our questions. Which then prompts the question, why do we even bother?
The “real” reason Pulcher was defeated so severely was that prior to the battle, Pulcher consulted with the sacred chickens, and he didn’t like the response. According to Roman tradition, caged sacred chickens were to be examined prior to a battle to determine the will of the gods. If the chickens ate offered feed, the gods favored battle. If they didn’t eat, going into battle would be a pretty bad idea. Pulcher’s chickens did not eat. Pulcher, angered by the sacred chickens, hurled their cages, chickens and all, into the sea, yelling, “If they won’t eat, let them drink!” Pulcher was fined specifically because of his disrespect toward the will of the gods, and the idea that if he had only listened to the chickens, he would not have suffered the loss.
This superstitious attitude did not die out with the Romans. Today, we are constantly bombarded with accusations that certain events would not have occurred were it not for our alleged disobedience of divine command. This is done with varying degree, ranging from allegations that allowing homosexuality to flourish in the United States was the cause of the death and destruction of 9/11,
to cubicle-mates becoming irate over a co-worker not desiring to say “Bless you” after someone sneezed, lest God punish the sneezer with a cold. Regardless of where the behavior falls upon the scale, it is irrational and illogical to attribute an incident to an alleged cause without linking the alleged cause and effect with more evidence than the mere observation that one happened before the other. That unsupported attribution is the post hoc, ergo propter hoc logical fallacy, often abbreviated as “post hoc.”
The post hoc fallacy exists when a causal conclusion is based solely on the supposed cause preceding the effect.
Post hoc, in the Pulcher case, is manifest as a superstitious bias toward jumping to a conclusion based on a coincidence. All of this is examined after the fact, with a seemingly righteous 20/20 hindsight perspective. Ah, it’s obvious that Pulcher would have lost the battle because the chickens predicted as much! Or, more succinctly, as a result of the will of the gods being made clearly against battle, Pulcher lost the battle. One caused the other. Of course, even if the gods had favored the battle (or, more specifically, if the chickens ate), Pulcher would probably still have lost (if the conditions otherwise had not changed).
Some common examples of the way this fallacy is used and abused in our media and society:
- Sex education causes promiscuity
- Video games cause children to be violent
- Prayer causes anything (lottery winning, healing, not getting caught running the red light… anything)
- Going to church causes anything good to happen in one’s life
- Missing church causes anything bad to happen in one’s life
- Having a homosexual parent causes a child to become homosexual (even if it’s not a biological child)
- Cursing causes the cursers and the listeners to be violent
There are many such examples. But there are also plenty of examples in which the effect has not yet happened, but, instead, is used as a threat. It certainly seems possible that reinforcement of existing alleged causal connections somehow strengthens the idea that a threatened effect is likely, at least to those who are easily swayed by such an abuse of logic. Examples of these threats are everywhere:
- If you don’t do/believe X, you will burn in hell
- If you don’t pray, you’ll make God sad. You’ll also make believers angry, and you’ll go to hell and burn.
- If you do something I don’t like (somehow supported by my favorite ancient text), God will hate you, I’ll hate you on behalf of God, and you’ll burn in hell
- The list goes on
Even if it’s not all fire and brimstone, any causal connection between an action or belief and a divine being’s judicial effect is unsupported by evidence. It is not only illogical to continue to make that false causal connection, but it is also what many would consider delusional. There is no more reason for someone to say, “I must not eat meat on Friday because it would offend God, as it is written,” than for someone else to say, “I must not step on a sidewalk crack lest it break my mother’s back.” If you did happen as a child to step on a sidewalk crack and then came home to find your mother had indeed fallen from the stairs and broken her back, you would probably have made a post hoc logical fallacy causal connection. It might take you years to grow out of the idea that you caused your mother to break her back by stepping on that crack, and perhaps you would never quite get over it. But it is that very childish superstition that is retained in believers ranging from the most mild to the most extreme — that there’s some supernatural greater being out there who accounts for every thought in every person’s head as it accounts for every grain of sand on every planet in every solar system in every galaxy in every universe in existence. It’s not a question of “Why would God break my mother’s back just because I stepped on a crack?” It’s rather a question of “Why would I, by default, attribute anything coincidental or anything I cannot otherwise quickly and easily explain to a supernatural, divine, or otherwise unnatural origin?”
What’s missing from the equation and from the general attitude of believers is a logical analysis of cause and effect. What needs to be distinguished is necessary versus sufficient condition. It’s logical to state that it is necessary that a cause precedes an effect. However, it’s not logical to state that merely because an event occurred prior to an effect that the event is the cause of the effect. That is because for the event to be a sufficient condition, it must be something that, if true, will result in the effect. If event P is true, then Q effect is true. If P then Q. So, what’s one of the most common logical fallacies used to justify religious faith? The formal logical fallacy called affirming the consequent, often abbreviated “miracle.” Spelled out in logic terms, looks like this:
If P then Q.
Q.
Therefore, P.
So, for example:
If prayer works (meaning prayer plus the existence of God), then Healing will occur.
Healing occurs.
Therefore, prayer works (and therefore God exists).
Although affirming the consequent is a fallacy, it’s one of the trickier in logic because if the consequent (Q) is actually true, that doesn’t necessarily mean P is not true. Quite often there’s a correlation (such as a coincidental proximity in time, or a consistency in occurrence) which makes it seem logical to assume that if the effect occurs, then it must be because of the purported cause.
Some examples of affirming the consequent:
- If I were a vampire, I would have long nails. I have long nails. Therefore, I am a vampire.
- If prayer works, then a prayed-for affliction would heal. A prayed-for affliction heals. Therefore, prayer works.
- If I mowed the lawn, then the grass will be short. The grass is short. Therefore, I mowed the lawn.
- If God exists, then Jesus could walk on water. Jesus walked on water. Therefore, God exists.
- If God exists, God will represent images of Jesus or Mary on toast. Images of Jesus and Mary have been represented on toast. Therefore, God exists.
These might at first either sound trivial or quite convincing, especially when a concept supported by this invalid type of argument has been infused into culture for thousands of years. However, just because it sounds good, and just because it has tradition backing it does not mean that it is logical. It is important to note that assertions of this invalid argument are rarely made as straightforwardly as noted. Generally, the representation shifts the language. For example, the latter example would likely be stated: “I saw the image of Jesus on a piece of toast! It’s proof that God exists!” It’s the same argument as above, but presented in a way that attempts to be more convincing. “I prayed all night for my child’s fever to dissipate. This morning, the fever dissipated. That’s proof that prayer works.” Same argument, different (potentially intentionally misleading) presentation.
One might argue, correctly, that merely because it’s a fallacy does not negate the truth of the cause being the cause of the effect. Indeed, if a child’s fever dissipates after prayer, the healing could very well have occurred as a result of the praying. However, the argument doesn’t actually prove that. The reason this is a logical fallacy is that one may not use affirming the consequent as a means by which to prove that the purported cause is true merely because the effect is true. The way to prove P is to prove that Q could not have occurred but for P. In other words, one would have to rewrite the equation to read:
If Q, then P.
Q.
Therefore, P.
If there is prayer, there will be healing.
There is prayer.
Therefore, there will be healing.
If I have long nails, then I am a vampire.
I have long nails.
Therefore, I am a vampire.
Although these may look very similar to the logical fallacies above, they are not logical fallacies. This is because they are valid. If the premises are true, then the conclusion must be true. That’s what makes a valid argument.
Compare:
If I were a vampire, I would have long nails.
I have long nails.
to
If I have long nails, I would be a vampire.
I have long nails.
In the first instance, it is easy just to say, so what? According to that premise, plenty of non-vampires could still have long nails, and that wouldn’t make them vampires. However, in the second example, having long nails is a sufficient condition for being a vampire (at least according to the premise). So, if that premise were true, and I have long nails, then, indeed, I would be a vampire. If the first example’s premise were true, and I had long nails, I might or I might not be a vampire. The argument certainly would not confirm. What can be said about the latter argument — If I have long nails, then I am a vampire, I have long nails, therefore, I am a vampire — is that it is unsound. The reason it is unsound is that at least one premise is not true. I have long nails, but I am not a vampire, despite the fact that the premise says that if I have long nails, then I would be a vampire. It’s obviously wrong. Therefore, despite the validity of the argument, it’s not a good argument. A good argument exists when it is valid and the premises are true.
When someone states that healing having occurred after prayer was a result of prayer (and therefore implicitly or explicitly a result of a diving being granting the prayer), that person is manifesting the logical fallacies of post hoc and affirming the consequent, and is also using an unsound argument, because nothing in the argument confirms the veracity of the premise that prayer works or that God exists. We can determine the unsoundness of the valid prayer argument by praying for healing and not having healing occur. It’s unsound because the premise “if there is prayer, there will be healing” means exactly what it says: prayer manifests healing. If it doesn’t, then it’s false.
What generally happens at that stage of discussion is that a believer will state something to the effect of, “Prayer doesn’t work like that.” Or, “You’re not doing it right.” If that’s the case, then the premise must be properly adjusted to reflect how it works or how to do it right. Ultimately, purported miracles are not a good way to try to prove the existence of a very specific deity, for the believer will undoubtedly fall into a post hoc/affirming the consequent trap.
Whenever I encounter someone who leans so heavily on these false arguments as to live life by edicts that would perhaps be validated if the arguments were true, I generally respond, “Prove it.” If the discussion survives the cause/effect analysis above, I’m often given the imperative that I must disprove something — mostly, “Prove that this isn’t a miracle of God!” Then the discussion usually devolves into an argument regarding burden of proof — worthy of its own article on another day. In the meantime, remember Claudius Pulcher and his chickens that were probably just overfed by a disgruntled Roman soldier — don’t fall for the post hoc + affirming the consequent logical fallacy, regardless of which side you choose to represent.
-Procrustes