Accident Fallacy

I. Definition

An accident fallacy is an error in reasoning caused by sweeping generalizations. It occurs when you assume that a rule-of-thumb applies to everyone or every situation, including obvious exceptions. While generalizing helps make the world easier to understand, often generalizations do not apply to every situation. An accident fallacy is using such a generalization to draw an incorrect conclusion about an obvious exception.

A good example of an accident fallacy could be assuming that ‘birds can fly’ applies to all birds, and therefore arguing, or even just believing, that a penguin can fly. While the statement that birds can fly is not false – because most birds can fly — penguins are an exception. Penguins are among the limited number of flightless birds and it would be logically fallacious to conclude otherwise based on the premise ‘birds can fly.’


II. Examples of Accident Fallacy

Example in Law

Many of you would not disagree that it is wrong to cut people with knives, and this is supported by the law. However, surgeons use scalpels to cut people open every day, and that’s both legal and, most of us would say, moral. In this case, it would be illogical to argue that surgery is wrong or should be illegal based on the statement that it’s wrong to cut people with knives. Surgery is an obvious exception, and almost all of us know that.

Example in Health

Another statement that could fall victim to the accident fallacy is that exercise is good for you. In most cases, that’s true. People benefit from staying active and regularly exercising. However, if you’re very sick, say you have pneumonia, you shouldn’t be exercising. In this case, you should be resting and allowing your body to recover. It would be an accident of fallacy if you were told it would be good for you to go exercise while suffering from pneumonia.

III. How to Avoid an Accident Fallacy

Avoiding an accident of fallacy requires that you think critically about generalized statements. Do not accept them at face value; be sure to really think about whether they apply to the situation you are evaluating. Most, even perhaps all, generalized statements have exceptions.  Don’t assume a general statement is always true unless you have proved it.