In this chapter we are concerned with certain recurrent mistakes in reasoning which, just because they are very common, have been singled out by logicians and labelled with more or less appropriate names. The world ‘fallacy’ has unfortunately often been used in different senses. It is used sometimes as a synonym for ‘error of fact’, as in the statement: ‘It is a fallacy to suppose that aeroplanes can be built by mass-production.’ This is, in my opinion, a plainly erroneous use of the word. The speaker meant that aeroplanes cannot, in fact, be produced by methods suitable to the production of, say, motor-cars. I shall assume without further discussion that the speaker, in using ‘fallacy’ in this sense, was simply showing his ignorance of the correct usage of the word. There remains to be noticed an ambiguity that is more important for our present purpose. If we say: ‘He is guilty of a fallacy’, we sometimes mean to imply that he is guilty of a deception. The Shorter Oxford English Dictionary gives as a meaning of ‘fallacy’, now obsolete, ‘deception’, ‘trickery’. This obsolete meaning does, I think, influence our modern usage. It would certainly be an advantage if we recognized that to accuse a person of having committed a fallacy is not to accuse him of intent to deceive. A fallacy is a violation of a logical principle; ‘to fall into a fallacy’ is to slip into ‘an unsound form of argument’, that is, to make a mistake in reasoning, not in what is reasoned about. If we mistakenly suppose that we have premisses adequate to establish our conclusion, then we are reasoning illogically and thus committing a fallacy.
(L. Susan Stebbing, Thinking to Some Purpose [Harmondsworth, UK: Penguin Books, 1939], 156-7 [italics in original])
Note from KBJ: Susan Stebbing is a careful thinker and one of my favorite philosophers, but she is mistaken here. The New Oxford American Dictionary (3d ed., 2010) defines “fallacy” as “a mistaken belief, esp. one based on unsound argument.” The word “especially” indicates that the word is not limited to mistaken beliefs that are based on unsound arguments but extends to mistaken beliefs generally. Scholars in general, and philosophers in particular, are arrogant, by which I mean that they arrogate words to themselves. Philosophers don’t own the word “fallacy”; they merely use it in a particular (technical) way. If a philosopher, in a philosophical context, used the word “fallacy” to mean “mistaken belief,” then he or she would be rightly criticized; but Stebbing is criticizing non-philosophers for using the word in other than the technical philosophical way. This is disciplinary arrogance. We might call it philosophism (the analogue of scientism).
