An argument is valid if and only if its premises could not jointly be true and its conclusion false. 'Even if your premises were true, I wouldn't have to accept your conclusion.' I've never heard of the notion of validity itself being question. The underpinnings of a formal system, the stopping places, cannot themselves be supported in the way that the particular deductive moves they themselves support are by them supported. But this doesn't mean there's some doubt as to whether arguments of the form 'if p, then q, p, therefore q,' are valid or not.
My understanding (which may be mistaken) is that, for P there is "some doubt" always - not in the subjective sense of feeling uncertain (after all, we can subjectively feel completely certain of what is objectively false) but in the objective sense that any assertion - including one of the logical connect between given propositions - has (as P puts it in "All Life Is Problem-Solving") a "_moment of uncertainty_". Put another way:- any assertion, including those as to the validity of deductive inferences, is possibly or potentially mistaken.
DonalI pray, and I think we should all so pray that Donal is indeed "mistaken" that "any assertion, including those as to the validity of deductive inferences, is possibly or potentially mistaken." This is an extremely radical position, fit, metaphorically speaking, to put quicksand under the basis of all our mutual understanding, unless Donal is saying, in effect, "not to worry--even if a given assertion as to the validity of deductive inferences is mistaken, that would not preclude the validity of deductive inferences so asserted." I'm afraid it is significant, that is, it is "educational" that Donal is having semantic issues with the word "validity." A sound argument is not a valid argument. The avoidance of contradictions in one's arguments is one step in the direction of a sound argument, but no guarantee of its validity.
I believe it was also enlightening, revealing, "educational," that Donal once maintained that the better argument often loses. He somehow conceives of arguments as being measurable, rankable on some kind of objective scale of validity, with the surprising consequence being that the better argument achieves, so to speak, an inner victory, something of a moral victory, because it is, "in fact," right, or, in Donal's terms, valid. But no mere mortal can determine the true validity, literally the "strength" of an argument, its "rightness," somehow objectively. Not to put too fine a point on it, but is not Donal's--for the most part--uncritical acceptance of Popper simply the outgrowth of his philosophical tendency to take his current favorite philosopher as the gold standard of argumentation?
Wittgenstein is far more modest--and he'd probably have taken a poker to anyone who claimed some mysterious high ground from which to judge the mistaken efforts of those "below," one of those fortunate few who believe themselves to be operating on some higher plane from which they can establish the "sense of the world":
TLP 6.4 All propositions are of equal value. TLP 6.41The sense of the world must lie outside the world. In the world everything is as it is and everything happens as it happens; _in_ it there is no value--and if there were, that value would have no value.
If there is a value that has value, it must lie outside everything happening and being as it is, because everything happening and being as it is, is accidental.
That which makes it non-accidental cannot lie _in_ the world, because otherwise that would again be accidental.
It must lie outside the world. TLP 6.42 Therefore there can also be no propositions of ethics. Propositions can express nothing higher. TLP 6.421 It is clear that ethics cannot be expressed. Ethics is transcendental. Ethics and aesthetics are one. Richard Henninge University of Mainz ------------------------------------------------------------------ To change your Lit-Ideas settings (subscribe/unsub, vacation on/off, digest on/off), visit www.andreas.com/faq-lit-ideas.html