43 ideas
16440 | I don't think Lewis's cost-benefit reflective equilibrium approach offers enough guidance [Stalnaker] |
16468 | Non-S5 can talk of contingent or necessary necessities [Stalnaker] |
16449 | In modal set theory, sets only exist in a possible world if that world contains all of its members [Stalnaker] |
14249 | Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley] |
10830 | Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos] |
10829 | A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos] |
16464 | We regiment to get semantic structure, for evaluating arguments, and understanding complexities [Stalnaker] |
16465 | In 'S was F or some other than S was F', the disjuncts need S, but the whole disjunction doesn't [Stalnaker] |
13733 | Frege considered definite descriptions to be genuine singular terms [Frege, by Fitting/Mendelsohn] |
10832 | '∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos] |
9874 | Contradiction arises from Frege's substitutional account of second-order quantification [Dummett on Frege] |
10834 | Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos] |
13841 | Why should compactness be definitive of logic? [Boolos, by Hacking] |
18252 | Real numbers are ratios of quantities, such as lengths or masses [Frege] |
18271 | We can't prove everything, but we can spell out the unproved, so that foundations are clear [Frege] |
10833 | Many concepts can only be expressed by second-order logic [Boolos] |
10623 | Frege defined number in terms of extensions of concepts, but needed Basic Law V to explain extensions [Frege, by Hale/Wright] |
9975 | Frege ignored Cantor's warning that a cardinal set is not just a concept-extension [Tait on Frege] |
18165 | My Basic Law V is a law of pure logic [Frege] |
16434 | Some say what exists must do so, and nothing else could possible exist [Stalnaker] |
16439 | A nominalist view says existence is having spatio-temporal location [Stalnaker] |
16443 | Properties are modal, involving possible situations where they are exemplified [Stalnaker] |
16471 | I accept a hierarchy of properties of properties of properties [Stalnaker] |
16452 | Dispositions have modal properties, of which properties things would have counterfactually [Stalnaker] |
16467 | 'Socrates is essentially human' seems to say nothing could be Socrates if it was not human [Stalnaker] |
16453 | The bundle theory makes the identity of indiscernibles a necessity, since the thing is the properties [Stalnaker] |
16466 | Strong necessity is always true; weak necessity is cannot be false [Stalnaker] |
16438 | Necessity and possibility are fundamental, and there can be no reductive analysis of them [Stalnaker] |
16436 | Modal concepts are central to the actual world, and shouldn't need extravagant metaphysics [Stalnaker] |
16433 | Given actualism, how can there be possible individuals, other than the actual ones? [Stalnaker] |
16437 | Possible worlds are properties [Stalnaker] |
16444 | Possible worlds don't reduce modality, they regiment it to reveal its structure [Stalnaker] |
16445 | I think of worlds as cells (rather than points) in logical space [Stalnaker] |
16454 | Modal properties depend on the choice of a counterpart, which is unconstrained by metaphysics [Stalnaker] |
16450 | Anti-haecceitism says there is no more to an individual than meeting some qualitative conditions [Stalnaker] |
16474 | How can we know what we are thinking, if content depends on something we don't know? [Stalnaker] |
9190 | A concept is a function mapping objects onto truth-values, if they fall under the concept [Frege, by Dummett] |
13665 | Frege took the study of concepts to be part of logic [Frege, by Shapiro] |
16461 | We still lack an agreed semantics for quantifiers in natural language [Stalnaker] |
16448 | Possible world semantics may not reduce modality, but it can explain it [Stalnaker] |
16442 | I take propositions to be truth conditions [Stalnaker] |
16447 | A theory of propositions at least needs primitive properties of consistency and of truth [Stalnaker] |
16446 | Propositions presumably don't exist if the things they refer to don't exist [Stalnaker] |