What's a name for the fallacy of concluding something must be based on truth because it is successful?

Question

I have noticed a type of fallacious reasoning that conflates truth and success. For example, a company might assume their predictive models are correct because these models make the company more money. However, turns out this was a conflation of success and truth; those models were incorrect. A few years later, the models will collapse or make incorrect predictions and it will be revealed that they were based on shoddy or untrue principles all along. The fact the system predicts the outcome does not imply the system is based on the true principles underlying the system.

There are other cases this fallacy in history. Genghis Khan, for example, sent letters (e.g. to the Shah of Bukhara) arguing that his lightning-fast conquests were proof that his Mongol forces were blessed or guided by God. The Muslims made the same argument after they conquered an area almost the size of the Roman Empire in two centuries. Countless groups argue that their success, growth, or size is proof of their validity or even religious truth.

Another example is in science. Ptolemy's model of astronomy explained the motion of the heavens by assuming each planet moved on a sphere called an epicycle (see full explanation). It also placed the Earth at the center of the solar system. Its predictive success was unsurpassed until Copernicus, and it is still used by planetarium projectors to model the solar system. However, we now know it is a woefully inaccurate description of the universe. In retrospect, it seems clearly fallacious to conclude the Ptolemaic model is true because it was successful.

Do you agree that arguments of this form are fallacious? Does this fallacy have a name?

Answer 1

The fallacy you're hinting can be characterized broadly as the false cause fallacy. Britannica defines the fallacy as follows:

The fallacy of false cause (non causa pro causa) mislocates the cause of one phenomenon in another that is only seemingly related.

That being said, the question you ask is quite interesting. While I agree the proposition

P: If X is successful in regards to a certain goal, then X is necessarily true

is quite strong and suspect, the weaker probabilistic form of the proposition isn't as problematic (as with many propositions which are framed in terms of probability), which is

'P: If X is successful in regards to a certain goal, then X is probably true

In fact, many scientific realists actually use a form of the above weaker premise to argue for scientific realism. The Standford Encylopedia of Philosophy states:

The most powerful intuition motivating [scientific] realism is an old idea, commonly referred to in recent discussions as the “miracle argument” or “no miracles argument”, after Putnam’s (1975a: 73) claim that realism “is the only philosophy that doesn’t make the success of science a miracle”. The argument begins with the widely accepted premise that our best theories are extraordinarily successful: they facilitate empirical predictions, retrodictions, and explanations of the subject matters of scientific investigation, often marked by astounding accuracy and intricate causal manipulations of the relevant phenomena. What explains this success? One explanation, favored by realists, is that our best theories are true (or approximately true, or correctly describe a mind-independent world of entities, laws, etc.). Indeed, if these theories were far from the truth, so the argument goes, the fact that they are so successful would be miraculous. And given the choice between a straightforward explanation of success and a miraculous explanation, clearly one should prefer the non-miraculous explanation, viz. that our best theories are approximately true (etc.).

_{(emphasis mine)}

Obviously, there are objections which are raised to the so-called "miracle argument" (see the linked article). It should also be noted that while 'P could be plausibly argued for in a scientific domain, in other domains (such as a business) it may not apply as well. Nevertheless, I think it is clear that the falsity of 'P (the weaker form of P) is not so obvious that it would rise to the level of an informal fallacy.

Answer 2

This is the fallacy of questionable cause, one of the best known, and most common informal fallacies. It is closely related to affirming the consequent which is a formal fallacy where a statement of the form "If X then Y" is misinterpreted as implying "If Y then X." You often hear this warned against with the statement "correlation does not imply causation," meaning that just because two things occur together, it does not imply that one causes the other. As with all informal fallacies, it takes its strength from its similarities to a stronger argument. With properly designed and controlled experiments, it is indeed sometimes possible to infer a cause from an effect.

Questionable Cause: Concluding that one thing caused another, simply because they are regularly associated.
https://www.logicallyfallacious.com/tools/lp/Bo/LogicalFallacies/148/Questionable-Cause

My initial intuition is that the religious case is different --but is it really? This is still a "questionable" cause in the religious case. We can't definitively call it false --it might be true --but we can judge that the evidence falls short of the claim. (It's not fallacious, however, to say that the evidence is "consistent with" the claim.) It's important to note, however, that the weakness of the argument does not, in itself, provide evidence AGAINST the claim. Even if Khan is wrong (about his victories proving his religion), that does not prove his religion is wrong as well.

It's worth noting that the Bible does address this specific dilemma directly. The Old Testament reports several instances where the adherents of different religions are challenged to perform the same miracle under the same circumstances. This is essentially a controlled experiment where the variable being tested is what religion is being invoked. (Also of interest: Jesus's statement that "Good fruit comes from good trees; bad fruit from bad trees" --but that's a whole other discussion).