Adverse Consequences

David Vander Laan

If the six men win, it will mean that the police are guilty of perjury, that they are guilty of violence and threats, that the confessions were invented and improperly admitted in evidence and the convictions were erroneous....

Lord Denning in his judgment on the Birmingham Six, quoted in Catherine Elliot and Frances Quinn, English Legal System

The argument from adverse consequences has this general form:

(1) If P were true, then something bad would be the case.

(2) Therefore, not P.

Since the bad consequences of P are not generally relevant to P’s truth or falsity, arguments of this form typically commit a fallacy of relevance. Here are some examples:

If we’re required to declare rental income to the Internal Revenue Service, then I’ve been calculating my taxes incorrectly for about six years. I’d have to collect a lot more information, and I’d worry about an audit of the previous years. So I think we don’t really have to report rental income.

Margaret Chemise says to Claude Nads: “I was reading about a sociolo­gist who has found that there are differences in the average intelligence of different racial groups. She found this out by conducting what she claims was a culturally neutral IQ test.” Claude responds: “Well she must have got it wrong. There isn’t an average difference in IQ between different races of people because if there was, it would allow bigots to justify their racism.” (Clark and Clark 2014, 25)

I am a busy man; I have no time for the long course of study which would be necessary to make me in any degree a competent judge of certain ques­tions, or even able to understand the arguments. [So I need not always have evidence for what I believe].

Of course, the conclusion of such an argument could turn out to be correct. But if the conclusion is a factual statement (i.e., a true or false statement, as opposed to a proposal for action), we cannot show that it is true simply by pointing out that its negation would have unfortunate consequences. After all, unfortunate things often do happen.

A common variant of the fallacy has this form:

(1) If people believed that P, then something bad would be the case.

(2) Therefore, not P.

The example about alleged IQ differences between races can be interpreted as an argument of this form. We might take Claude’s thought to be that the belief in IQ differences would allow bigots to justify their racism. Here’s another example:

Are human beings physical objects such as biological organisms, or do they have immaterial souls? New psychological evidence sheds light on this ancient dispute between physicalism and dualism. A recent survey found that people who affirm dualist beliefs are more likely than physi- calists to have reckless attitudes toward health and fitness. Dualists were also found to prefer and eat less healthy food than physicalists. These results suggest that adopting dualism may well have a negative impact on health-related behaviors.

Here, as often, the conclusion is not entirely explicit. However, the second sentence suggests that the intended conclusion is that dualism is probably false. Even if it were true that believing dualism had negative effects on one’s health, though, those effects would not be closely related to the matter of whether dualism or physicalism is correct. (This example also includes a dubious inference from correlation to causation.)

The argument from adverse consequences can be seen as an argument that is intended to be pragmatic - about what we should do, not about what is true - but then comes to the wrong kind of conclusion. The arguer may intend to use a form like this:

(1) If P were true, then something bad would be the case.

(2) Therefore, we should hope that not P.

Or this:

(1) If people believed that P, then something bad would be the case.

(2) Therefore, we should not believe that P.

But the arguer instead conflates one of the above conclusions with the unsupported claim that P is false.

It is possible that the pragmatic argument lurking behind the fallacy is faulty as well. It may be that P has bad consequences but also very good ones, and so we should hope that P, all things considered. Or it may be that, although some bad things would result from the belief that P, we have a moral obligation to form our beliefs truthfully regardless of the results. But whether the pragmatic argument is faulty or not, the adverse consequences usually have very little to do with whether P is true or false.

In many genuinely pragmatic arguments, however, adverse consequences are relevant to the conclusion and no fallacy is committed. So it is important to notice exactly what the conclusion of the argument is. Consider the thought process described below:

For the physicians who ran the ASCC, popular interest in meat and other foods as causes of cancer threatened to undermine [an early detection and treatment] approach to cancer control.... On the one hand, if people believed that their diet was healthy and unlikely to cause cancer, they could easily use this as a reason to avoid their physician if they spotted any of the early warn­ing signs of cancer. On the other hand, if they believed that their diet was unhealthy and might be the cause of cancer they could easily succumb to a paralyzing fear that nothing was to be done.. Either way, the result was likely to be that people waited too long to see their physician.. From this perspective, the ASCC believed, it was better to question any role for diet as a cause of cancer than to risk giving people an excuse not to seek early treatment. (Cantor, Bonah, and Dorries 2015, 117)

The ASCC’s conclusion was that they should question the idea that diet plays a role in causing cancer; it was a conclusion about what they should do.

So when you suspect that someone has given an argument from adverse consequences, first identify the conclusion. Sometimes you will find the con­fusion characteristic of the fallacy, in which a pragmatic conclusion has been conflated with a factual conclusion. Sometimes - rather frequently, in fact - you will find that the arguer has not settled on a conclusion, or at any rate has left the conclusion implicit. In that case the arguer may be in danger of committing the fallacy without yet having done so. Sometimes the arguer may have a pragmatic conclusion in mind without confusing it with a factual conclusion.

And sometimes it will be unclear. Lord Denning’s conclusion in the quota­tion at the beginning of this chapter may appear to be a pragmatic one. On the other hand, it also seems likely that he intends to decide what to do on the basis of the factual statements he believes, for example, that the police have not committed perjury. Since the “appalling” character of the situation (assuming the police did commit perjury and so on) does not do much to support those factual statements, it is likely that he has implicitly made an argument from adverse consequences.

References

Cantor, David, Christian Bonah, and Matthias Dorries, eds. 2015. Meat, Medicine and Human Health in the Twentieth Century. New York: Routledge.

Clark, Jeff, and Theo Clark. 2014. Humbug! The Skeptic’s Field Guide to Spotting Fallacies and Deceptive Arguments. New York: Nifty Books.

Clifford, W.K. 1876. “The Ethics of Belief.” Contemporary Review (29): 289-309 Elliot, Catherine, and Frances Quinn. 2007. English Legal System. London: Longman Publishing Group.