What is a logical fallacy?
A “fallacy” is a mistake, and a “logical” fallacy is a mistake in reasoning. There are, of course, other types of mistake than mistakes in reasoning. For instance, factual mistakes are sometimes referred to as “fallacies”. However, the Fallacy Files is specifically concerned, not with factual errors, but with logical ones. In logic, the term “fallacy” is used in two related, but distinct ways. For example: • “Argumentum ad Hominem is a fallacy.” • “Your argument is a fallacy.” In 1, what is called a “fallacy” is a type of argument, so that a “fallacy” in this sense is a type of mistaken reasoning. In 2, it is a specific argument that is said to be a “fallacy”, so that in this sense a “fallacy” is an argument which uses bad reasoning. Clearly, these two senses are related: in 2, the argument may be called a “fallacy” because it is an instance of Argumentum ad Hominem, or some other type of fallacy. In order to keep these two senses distinct, I restrict the term “fallacy” to the first se
