This fallacy occurs when someone infers that only one cause is responsible for an effect without considering that there might be multiple causes. This fallacy has the following form:
Premise 1: Effect E occurs.
Premise 2: C is a cause of E.
Conclusion: Therefore, C is the single cause of E.
This is an error because the possibility of multiple causes must be considered in causal reasoning. This fallacy often occurs because sorting out complicated casual situations is difficult, and it is easier to focus on one alleged cause.
In some cases, people commit this fallacy in (good faith) ignorance by failing to consider that the causal situation might be more complicated than they think.
In other cases, this fallacy is used intentionally to get people to think that there is a single cause for an effect. This is often done for political reasons with the single cause matching the political agenda of the person using the fallacy. For example, a politician might claim that price increases are due entirely to corporate profiteering while not mentioning the effects of such things as supply chain issues and increased demand.
It is important to note that this error can occur when there is only a single cause. As with all fallacies of reasoning, the error is not a factual one. Even if the conclusion is true, if the person making the claim fails to consider the possibility that there are multiple causes, then they have committed this fallacy. Naturally, some situations might so obviously be cases of a single cause that minimal effort is required to eliminate the possibility of multiple causes. Other cases can be more complicated.
A person can focus on a single cause without committing this fallacy, provided that they are not erroneously concluding that there must be a single cause. For example, while there are many causes of forest fires a specific mitigation plan might focus only on one cause for various practical reasons.
Defense: While causal reasoning can be difficult, avoiding this fallacy is easy: when engaged in causal reasoning, be sure to consider that a single effect might have multiple causes.
Rick: “It looks like our schools are in rough shape. I saw that Americans are lagging way behind the rest of the world in areas like math and science.”
Ed: “Yup. It is those stupid teacher unions. They ruined education. If we could just get rid of the unions, we’d be on top of the world again.”
“The recent economic meltdown was an incredible financial disaster. However, nothing has been done to address its cause, namely allowing mortgage companies to make subprime loans.”
“It is obvious what the cause of violent crime is. The destruction of the traditional family by the woke folks has brought blood to our streets.”
“It is obvious what the cause of violent crime is. The greed of the rich has brought blood to our streets.”