Wednesday, January 17, 2007

2.21 A picture either agrees with reality or does not; it is correct or incorrect, true or false.

If it follows that a proposition is essentially such that it can be true or false, then there can be no necessary truths or necessary falsehoods expressible in propositions. Apparently Hacker thinks this “bipolarity principle” is both rooted in an intuition (and hence rather indefensible) and hugely important. McManus argues against this view on p. 59.


N. N. said...

If bivalence (and therefore, non-contradiction) is indefensible, the very idea of defending a claim is incoherent. I wonder what Hacker means (what's the page number in Insight and Illusion).

DR said...

Thanks n.n. I realize now that "indefensible" is a bad word for me to have used here. I mean impossible to defend (because it is simply intuitively obvious), not impossible to accept.

According to McManus (and I haven't checked this, but I think he's right) Hacker believes that every proposition is either true or false. It does not follow from that (surely?) that the idea of defending a claim is incoherent. I'm not sure that I have understood your point, but I suspect you have been misled by my poor choice of words.