Cumulative case argument

Cumulative Case Argument

If religious apologists had a good argument for believing in god—just one good argument, by which I mean one argument that any reasonable person would embrace—they would have provided it. Lacking such a good argument, they have chosen to concoct as many not-so-good arguments as they can. Some of these arguments are sophisticated and they often sound reasonable when first encountered. But, as the astounding proliferation of atheism among modern philosophers attests, none of the arguments withstand careful scrutiny. The end result of this proliferation of flawed apologetic arguments is that authors like me are forced to write longer books than we otherwise would and readers are required to examine the arguments with a great measure of diligence.

That’s not an altogether bad thing. The unexamined life is probably not as enriched as the examined life. Notice that I don’t go as far as Socrates, who declared that the unexamined life is not worth living. Surely Socrates must have noticed that even many individuals who are mentally impaired still cherish their lives. In fact, people who think too much tend to be miserable. If you ever see me attached to life support and someone says that I am in a vegetative state, please don’t let them pull the plug. I might be having a really good time.

That said, my book Religion Refuted provides a fairly thorough examination of every major theological argument. Among those arguments is the cumulative case argument—the theologians’ last ditch effort to snatch victory from the jaws of defeat.

The cumulative case argument holds that, though each natural theology argument is imperfect, each contributes at least marginally toward justifying belief in God. Collectively, the full suite of natural theology arguments allegedly combine to make an adequate case for God.

What qualities would a cumulative case argument need to possess in order to succeed? For starters, it would have to encompass only those apologetic arguments that can be assigned a probability. For example, we might say that the design argument has a 0.1 probability (a 10 percent chance) of being correct. Assigning these probabilities would in itself be a challenging and contentious project. The apologists’ goal would be to accumulate at least enough probability points to cross the .5 probability threshold.

Of course, we’d have to include in our set of arguments only those that work toward proving the same god concept. An argument specifically for Islam would count as an argument against Christianity and vice versa. We must restrict the definition of god to the most generic compatible with the entire set of arguments being included in the mix. In other words, our cumulative argument would establish only the lowest common denominator.

We would then have to subtract probability points for each counter-apologetic argument. For instance, if someone argued that God designed the human skeletal system, the counterargument would cite evolutionary theory, which educated people deem highly probable. As you can see, it is arithmetically impossible for a collection of losing arguments to be summed up to build a winning case unless we exclude competing arguments, the arguments they individually lost to.

It seems arbitrary and biased to exclude effective counter-arguments, but suppose we did. What then do we do with those ineffective counter-arguments? Surely there are counter-apologetic arguments that are of poor quality. What happens if we fail to exclude them as well? Every poor quality argument that skeptics invent, as long as it has even the slightest probability of being correct, still strengthens the overall case against God. That’s according to the rule we used for summing up the religious arguments.

It might seem that this would encourage quantity over quality, but not necessarily. If there were a single counter-apologetic argument that revealed the logical impossibility of the god being proposed, the cumulative case would catastrophically fail. In that case, we would not be in a position of weighing one argument against another. That would be unnecessary if we had a single argument that logically disqualifies the purported conclusion. As I explain in Religion Refuted, numerous devastating counter-apologetic arguments of this nature militate against the traditional Abrahamic god. But for the purposes of the present discussion, we will assume that no such counter-apologetic argument exists.

Alright, now that we’ve laid out the ground rules, let’s consider an example of a cumulative case argument. I am going to deliberately present a flawed case, one that is not believable. In fact, I will purposefully make it silly. That sounds like a waste of time, but bear with me because this example illustrates a vital point. In this example, I will offer a cumulative case for invisible leprechauns with bad hair.

If I hypothesize that these leprechauns steal socks, then I could say that every missing sock is evidence of the leprechauns. Not good evidence, granted, but it doesn’t have to be good evidence, because all I need is enough missing socks over time to add up to a compelling case for the existence of the leprechauns. According to my calculations, even if the missing sock argument has a probability of only one billionth of one percent, and even if the vast majority of people on Earth never lost a single sock and the rest of us lost only one pair of socks during our entire lifespans, the existence of the sock-stealing leprechauns would have accumulated enough probability points by this time in human history to make the case for leprechauns more probably true than false.

If I hypothesize that these leprechauns also make people drop things, then every time someone drops something I chalk up more proof that the leprechauns are real. I can keep adding qualities, attributes, and bad habits to the leprechauns. Oddly enough, the more elaborate and fanciful I make my description of the leprechauns, the easier it becomes to prove their existence.

Clearly, there’s something wrong with this approach. Let’s explore why the cumulative case for leprechauns fails and then we can see if this same kind of failure afflicts the cumulative case for Jehovah.

In the leprechaun case, the fundamental problem appears to be that my evidence (missing socks) seems irrelevant to the conclusion (leprechauns). Why should a missing sock be accepted as evidence for invisible leprechauns? It’s a non sequitur. If we concede that a missing sock counts as even a tiny fraction of one percent of a case for invisible leprechauns, then we have established the fatal principle that enough missing socks amount to a slam dunk case for leprechauns.

We commit the same mistake in the case for Jehovah. When an apologetic argument for Jehovah fails, it fails completely. We can’t assume that something is evidence, even extraordinarily weak evidence, unless there is an established causal link between that evidence and the purported conclusion. The proponents of a cumulative case are exploiting our natural tendency to conflate our residual uncertainty when appraising the merits of an apologetic argument with the probability of its having merit.

A Christian apologist would almost certainly scoff at my comparison of Jehovah to invisible leprechauns. The apologist might recommend that we compare the case for Jehovah to the case for an event where we’re accustomed to thinking in probabilistic terms—perhaps, say, a home burglary. A creaking noise from behind a house, a crowbar lying on the ground, and a window that is slightly ajar bolster the case that a home burglary was in progress. The case for Jehovah is thought to be more like this burglary case.

But that is wrong. We can build a cumulative case for a home burglary because each of the individual pieces of evidence for the burglary is uncontested (or likely so) and these individual pieces of evidence combine to form a cohesive, unified narrative. In contrast, each apologetic argument is highly contested and each is a standalone argument rather than an integral part of a cohesive narrative.

I’m not arguing that a cumulative case can never be made in defense of religion. A cumulative case is appropriate when one is, say, building an argument that there was a historical Jesus. Documents such as the Gospel of Luke and the writings of Tacitus can converge toward a particular conclusion (that ancient people sincerely believed that Jesus was a historical person). The Luke and Tacitus documents are comparable to the creaking noise, crowbar, and open window in that they are extant pieces of evidence. Moreover, there is an established, though admittedly imperfect, causal link between written human testimony and real-world facts.

In contrast, the “missing socks” argument is a standalone argument with no track record as being causally related to the existence of invisible leprechauns. It therefore cannot be assigned a probability greater than zero. Likewise, each of the apologetic arguments put forward to prove Jehovah is a standalone argument with no track record as being causally related to the existence of Jehovah and therefore cannot be assigned a probability greater than zero. This explains why prosecutors can build a cumulative case that a burglary was in progress and why historians can build a cumulative case that Jesus existed, whereas we cannot build a cumulative case for beings like gods and invisible leprechauns with bad hair.

All the failed arguments for God should indeed have a cumulative effect on our judgment about the case for God, but the effect is the reverse of what the apologists suggest. The repeated failures by intelligent men and women throughout human history to prove God, despite their most passionate commitment to the project, indicates that the project is hopeless. This strengthens the case that supernatural beliefs are based on an inaccurate view of the cosmos. Perhaps we should call this the cumulative case for atheism.


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