6 ideas
14263 | Strong Kleene disjunction just needs one true disjunct; Weak needs the other to have some value [Fine,K] |
Full Idea: Under strong Kleene tables, a disjunction will be true if one of the disjuncts is true, regardless of whether or not the other disjunct has a truth-value; under the weak table it is required that the other disjunct also have a value. So for other cases. | |
From: Kit Fine (Some Puzzles of Ground [2010], n7) | |
A reaction: [see also p.111 of Fine's article] The Kleene tables seem to be the established form of modern three-valued logic, with the third value being indeterminate. |
17807 | To study formal systems, look at the whole thing, and not just how it is constructed in steps [Curry] |
Full Idea: In the study of formal systems we do not confine ourselves to the derivation of elementary propositions step by step. Rather we take the system, defined by its primitive frame, as datum, and then study it by any means at our command. | |
From: Haskell B. Curry (Remarks on the definition and nature of mathematics [1954], 'The formalist') | |
A reaction: This is what may potentially lead to an essentialist view of such things. Focusing on bricks gives formalism, focusing on buildings gives essentialism. |
17806 | It is untenable that mathematics is general physical truths, because it needs infinity [Curry] |
Full Idea: According to realism, mathematical propositions express the most general properties of our physical environment. This is the primitive view of mathematics, yet on account of the essential role played by infinity in mathematics, it is untenable today. | |
From: Haskell B. Curry (Remarks on the definition and nature of mathematics [1954], 'The problem') | |
A reaction: I resist this view, because Curry's view seems to imply a mad metaphysics. Hilbert resisted the role of the infinite in essential mathematics. If the physical world includes its possibilities, that might do the job. Hellman on structuralism? |
17808 | Saying mathematics is logic is merely replacing one undefined term by another [Curry] |
Full Idea: To say that mathematics is logic is merely to replace one undefined term by another. | |
From: Haskell B. Curry (Remarks on the definition and nature of mathematics [1954], 'Mathematics') |
14262 | Formal grounding needs transitivity of grounding, no self-grounding, and the existence of both parties [Fine,K] |
Full Idea: The general formal principles of grounding are Transitivity (A«B, B«C/A«C: if A helps ground B and B helps C, then A helps C), Irreflexivity (A«A/absurd: A can't ground itself) and Factivity (A«B/A; A«/B: for grounding both A and B must be the case). | |
From: Kit Fine (Some Puzzles of Ground [2010], 4) |
10994 | Conditionals are true if minimal revision of the antecedent verifies the consequent [Stalnaker, by Read] |
Full Idea: Stalnaker proposes that a conditional is true if its consequent is true in the minimal revision in which the antecedent is true, that is, in the most similar possible world in which the antecedent is true. | |
From: report of Robert C. Stalnaker (works [1970]) by Stephen Read - Thinking About Logic Ch.3 | |
A reaction: A similar account of counterfactuals was taken up by Lewis to give a (rather dubious) account of causation. |