ABSTRACT
In this chapter, we are concerned with inference as it can be observed when practised by someone else. Inference is supposed to be a mark of intelligence and to show the superiority of men to machines. At the same time, the treatment of inference in traditional logic is so stupid as to throw doubt on this claim, and syllogistic inference, which was taken as the type from Aristotle to Bacon (exclusive), is just the sort of thing that a calculating machine could do better than a professor. In syllogistic inference, you are supposed to know already that all men are mortal and that Socrates is a man; hence you deduce, what you never suspected before, that Socrates is mortal. This form of inference does actually occur, though very rarely. The only instance I have ever heard of was supplied by Dr. F. C. S. Schiller. He once produced a comic number of the philosophical periodical Mind, and sent copies to various philosophers, among others to a certain German, who was much puzzled by the advertisements. But at last he argued: ‘Everything in this book is a joke, therefore the advertisements are jokes.’ I have never come across any other
case of new knowledge obtained by means of a syllogism. It must be admitted that, for a method which dominated logic for two thousand years, this contribution to the world’s stock of information cannot be considered very weighty.
