A Descriptive Science of Logic

Abstract

§30. We often talk as though other people’s belief systems were illogical, irrational, incoherent; but a little reflection shows that this cannot be so — and not just on the punning grounds that an entirely irrational jumble of propositions could not be styled a belief ‘system’. If it were really true that your belief system had no internal logic or coherence, then it would be indistinguishable from a set of beliefs assembled at random: and, however long I spent finding out your beliefs on different topics, I would never get any better at predicting your answers to questions I had not yet asked. It is not my experience, nor do I think it is anyone’s, that belief systems are like this. If you tell me that British people should be prouder of their armed forces, that Mrs Thatcher helped make Britain great again, that you would go to prison for your right to measure things in feet and inches, that red tape from Brussels is stifling the economy, and that political correctness has gone mad, I do not expect you to add that you wish Britain had joined the single European currency. If you believe that it is morally wrong to eat the meat of animals, you oppose animal testing even of potentially life-saving drugs, and you think that human beings have a sacred duty to uphold animal rights, I shall be surprised if I discover that you also believe hunting is a fine rural sport that urban Greens fail to understand.²

Hoc inter nos et Tuscos […] interest: nos putamus, quia nubes collisae sunt, fulmina emitti; ipsi existimant nubes collidi ut fulmina emittantur.

This is the difference between us and the Etruscans […]: we think lightning is caused by clouds colliding, whereas they reckon the reason clouds collide is to cause lightning.

Seneca¹