Combining Texts

All the ideas for 'What is so bad about Contradictions?', 'The Source of Necessity' and 'What is Mathematical Truth?'

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7 ideas

2. Reason / B. Laws of Thought / 3. Non-Contradiction
Someone standing in a doorway seems to be both in and not-in the room [Priest,G, by Sorensen]
     Full Idea: Priest says there is room for contradictions. He gives the example of someone in a doorway; is he in or out of the room. Given that in and out are mutually exclusive and exhaustive, and neither is the default, he seems to be both in and not in.
     From: report of Graham Priest (What is so bad about Contradictions? [1998]) by Roy Sorensen - Vagueness and Contradiction 4.3
     A reaction: Priest is a clever lad, but I don't think I can go with this. It just seems to be an equivocation on the word 'in' when applied to rooms. First tell me the criteria for being 'in' a room. What is the proposition expressed in 'he is in the room'?
10. Modality / B. Possibility / 1. Possibility
Mathematics eliminates possibility, as being simultaneous actuality in sets [Putnam]
     Full Idea: Mathematics has got rid of possibility by simply assuming that, up to isomorphism anyway, all possibilities are simultaneous actual - actual, that is, in the universe of 'sets'.
     From: Hilary Putnam (What is Mathematical Truth? [1975], p.70), quoted by Stewart Shapiro - Philosophy of Mathematics 7.5
10. Modality / C. Sources of Modality / 1. Sources of Necessity
Explanation of necessity must rest on something necessary or something contingent [Hale]
     Full Idea: The dilemma is that to give the ultimate source of any necessity, we must either appeal to something which could not have been otherwise (i.e. is itself necessary), or advert to something which could have been otherwise (i.e. is itself merely contingent).
     From: Bob Hale (The Source of Necessity [2002], p.301)
     A reaction: [Hale is summarising Blackburn's view, and going on to disagree with it] Hale looks for a third way, but Blackburn seems to face us with quite a plausible dilemma.
Why is this necessary, and what is necessity in general; why is this necessary truth true, and why necessary? [Hale]
     Full Idea: We must distinguish between explaining particular necessities and explaining necessity in general; and we ought to distinguish between explaining, in regard to any necessary truth, why it is true, and explaining why it is necessary.
     From: Bob Hale (The Source of Necessity [2002], p.308)
     A reaction: Useful. The pluralist view I associate with Fine says we can explain types of necessity, but not necessity in general. If we seek truthmakers, there is a special case of what adds the necessity to the truth.
The explanation of a necessity can be by a truth (which may only happen to be a necessary truth) [Hale]
     Full Idea: My claim is that there are non-transitive explanations of necessities, where what explains is indeed necessary, but what explains the necessity of the explanandum is not the explanation's necessity, but its truth simpliciter.
     From: Bob Hale (The Source of Necessity [2002], p.311)
     A reaction: The big idea is to avoid a regress of necessities. The actual truths he proposes are essentialist. An interesting proposal. It might depend on how one views essences (as giving identity, or causal power)
10. Modality / C. Sources of Modality / 3. Necessity by Convention
If necessity rests on linguistic conventions, those are contingent, so there is no necessity [Hale]
     Full Idea: If the alleged necessity, e,g, 2+2=4, really does depend upon a convention governing the use of the words in which we state it, and the existence of that convention is merely a contingent matter, then it can't after all be necessary.
     From: Bob Hale (The Source of Necessity [2002], p.302)
     A reaction: [Hale is citing Blackburn for this claim] Hale suggests replies, by keeping truth and meaning separate, and involving laws of logic. Blackburn clearly has a good point.
10. Modality / C. Sources of Modality / 4. Necessity from Concepts
Concept-identities explain how we know necessities, not why they are necessary [Hale]
     Full Idea: It seems to me that identity-relations among concepts have more to do with explaining how we know that vixens are female foxes etc., than with explaining why it is necessary, and, more generally, with explaining why some necessities are knowable a priori.
     From: Bob Hale (The Source of Necessity [2002], P.313)
     A reaction: Hale rejects the conceptual and conventional accounts of necessity, in favour of the essentialist view. This strikes me as a good suggestion of Hale's, since I agree with him about the essentialism.