Hypothesis Contrary to Fact


From a statement of fact, the argument draws a counterfactual claim (i.e. a claim about what would have been true if the stated fact were not true). The argument falsely assumes that any state of affairs can have only one possible cause.



"If Napoleon had won the battle of Waterloo, we would all be speaking French right now."


"In this country citizens are permitted to own guns. If guns were outlawed, citizens would be unable to protect themselves and there would be an uncontrollable crime wave."


"Had Hillary [Clinton] won this election, you'd be at war right now with North Korea, and I have no doubt about that." - Donald Trump, July 25, 2019, in a telephone interview with Sean Hannity.



We know that actions have consequences. We are able to speculate about the consequences of our actions because there is a real causal connection between how we act and how things turn out. We avoid certain actions because we are able to understand those causal connections. Wise choices require an awareness of consequences and an ability to reason hypothetically about them. It is perfectly good reasoning to say, "I didn't turn left because, if I had turned left, I would have gotten lost." A teacher is entitled to say, "You got an F because you didn't turn in your assignments. If you had turned in your assignments, you wouldn't have gotten an F." This means, of course, that we can speculate on how matters might have turned out differently--for good or ill--if we had acted differently, or if history had been otherwise than it is.

The fallacy of Hypothesis Contrary to Fact appears to follow the same general pattern of reasoning, but it does not. In the fallacy of Hypothesis Contrary to Fact, the conclusion is a hypothetical statement, while the premiss is a statement of fact. We are inferring a connection between an antecendent and a consequent from the fact stated in the premiss. In the examples of legitimate hypothetical reasoning given in the paragraph above, the hypothetical statement is not the conclusion; it is one of the premisses. I take it as given that if I turn left, I will get lost, and then make my choices accordingly. The teacher takes it as given that if you had turned in your assignments you would not have gotten an F. The fact that you got an F is then explained by your poor choices. The conclusion of the argument is not a hypothetical statement; rather, the conclusion is, "You should have turned in your assignments."

It might be noted that the logical movement in Hypothesis Contrary to Fact should not be considered fallacious by logicians who subscribe to the truth-functional definition of "if...then..." According to truth tables, any "if...then..." statement is true unless its antecedent is true and its consequent false. Hence, knowing that the antecedent is false is enough to guarantee that a hypthetical statement is true. But this is precisely what Hypothesis Contrary to Fact does: it asserts that a hypothetical statement is true by assuring us that its antecedent is false. It is a valid argument form with a true premiss. Hence it cannot be considered fallacious. However, since it clearly is fallacious, I take it that there must be something deeply wrong with the truth-functional understanding of "if...then..." statements. Regrettably, this is not the place to try to resolve this difficult problem, which has plagued logicians for the last two thousand years.


Source: I first became aware of this fallacy from Max Schulman's marvelous short story, "Love is a Fallacy," published in The Many Loves of Dobie Gillis (1951). Although this is undoubtedly not the earliest reference to this fallacy, I have not so far been able to identify an earlier source.


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