8 ideas
12220 | Is it the sentence-token or the sentence-type that has a logical form? [Fine,K] |
Full Idea: Do we attribute a logical form to a sentence token because it is a token of a type with that form, or do we attribute a logical form to a sentence type because it is a type of a token with that form? | |
From: Kit Fine (Quine on Quantifying In [1990], p.110) | |
A reaction: Since I believe in propositions (as the unambiguous thought that lies behind a sentence), I take it that logical form concerns propositions, though strict logicians don't like this, for fear that logic spills into psychology. |
12222 | Substitutional quantification is referential quantification over expressions [Fine,K] |
Full Idea: Substitutional quantification may be regarded as referential quantification over expressions. | |
From: Kit Fine (Quine on Quantifying In [1990], p.124) | |
A reaction: This is an illuminating gloss. Does such quantification involve some ontological commitment to expressions? I feel an infinite regress looming. |
13768 | Validity can preserve certainty in mathematics, but conditionals about contingents are another matter [Edgington] |
Full Idea: If your interest in logic is confined to applications to mathematics or other a priori matters, it is fine for validity to preserve certainty, ..but if you use conditionals when arguing about contingent matters, then great caution will be required. | |
From: Dorothy Edgington (Conditionals [2001], 17.2.1) |
13770 | There are many different conditional mental states, and different conditional speech acts [Edgington] |
Full Idea: As well as conditional beliefs, there are conditional desires, hopes, fears etc. As well as conditional statements, there are conditional commands, questions, offers, promises, bets etc. | |
From: Dorothy Edgington (Conditionals [2001], 17.3.4) |
13764 | Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington] |
Full Idea: Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? Are they non-truth-functional, like 'because' or 'before'? Do the values of A and B, in some cases, leave open the value of 'If A,B'? | |
From: Dorothy Edgington (Conditionals [2001], 17.1) | |
A reaction: I would say they are not truth-functional, because the 'if' asserts some further dependency relation that goes beyond the truth or falsity of A and B. Logical ifs, causal ifs, psychological ifs... The material conditional ⊃ is truth-functional. |
13765 | 'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington] |
Full Idea: If it were possible to have A true, B false, and If A,B true, it would be unsafe to infer B from A and If A,B: modus ponens would thus be invalid. Hence 'If A,B' must entail ¬(A & ¬B). | |
From: Dorothy Edgington (Conditionals [2001], 17.1) | |
A reaction: This is a firm defence of part of the truth-functional view of conditionals, and seems unassailable. The other parts of the truth table are open to question, though, if A is false, or they are both true. |
4042 | Metaphysics requires the idea of people (speakers) located in space and time [Davidson] |
Full Idea: An intelligible metaphysics will assign a central place to the idea of people (= speakers) with a location in public space and time. | |
From: Donald Davidson (The Method of Truth in Metaphysics [1977], §III) | |
A reaction: The 'location' is the interesting bit, requiring people to be bodies, not abstractions. A big, plausible claim, but hard to prove. |
4041 | Sentences held true determine the meanings of the words they contain [Davidson] |
Full Idea: Sentences held true (the linguistic representatives of beliefs) determine the meanings of the words they contain. | |
From: Donald Davidson (The Method of Truth in Metaphysics [1977], §II) | |
A reaction: Maybe. Historically, truth and belief presumably precede words and sentences. But words separate off from beliefs very easily. I'm not convinced. Words initiate language, not beliefs? |