W. V. Quine and J. S. Ullian, The Web of Belief, pp. 12-13:

”It is important to distinguish between disbelief and nonbelief–between believing a sentence false and merely not believing it true. Disbelief is a case of belief; to believe a sentence false is to believe the negation of the sentence true. We disbelieve that there are ghosts; we believe that there are none. Nonbelief is the state of suspended judgment: neither believing the sentence true nor believing it false. Such is our attitude toward there being an even number of Paul Smiths in Boston. This is still nothing so contentious as believing the sentence to be neither true nor false, on the contrary, it is simply the absence of opinion.

English usage is perverse on the point: we say, confusingly, the weaker “I don’t believe so” to mean the stronger “I believe not.” But the fact is, taking any sentence at random, that belief and disbelief are less usual than nonbelief. Are there an even number of Paul Smiths in Boston? Will it rain in Pontiac next Labor Day? English being what it is, we answer “I don’t know,” because it would be misleading to say “I don’t believe so.” But our state is simply nonbelief.

The flight to “I don’t know” compounds the perversity of idiom, for knowing is quite a special kind of believing; you can believe without knowing. Believing something does not count as knowing it unless what is believe is in fact true. And even if what is believed is true, believing it does not count as knowing it unless the believer has firm grounds for belief. Emily knows that her name is “Emily”, having had firm and abundant evidence of it over the years, We must still count her as knowing it even though the cannot remember the evidence now. But Emily may merely believe and not know that the major is corrupt, corrupt though he is; for Emily has read only the innuendoes of the rival candidate.”

Sammenlign dette med mine skriverier om normalsproget, mangel og negation samt mit forslag til at bruge ‘disbelieve’ til at mane ‘tro det modsatte’.

Denne bog er fra 1970. Så denne gang er jeg kun omkring 35 år for sent. Det bliver bedre og bedre!

Bogen er tilgængelig på nettet her.1