28 ideas
18851 | Pairing (with Extensionality) guarantees an infinity of sets, just from a single element [Rosen] |
11022 | Gentzen introduced a natural deduction calculus (NK) in 1934 [Gentzen, by Read] |
11065 | The inferential role of a logical constant constitutes its meaning [Gentzen, by Hanna] |
11023 | The logical connectives are 'defined' by their introduction rules [Gentzen] |
11213 | Each logical symbol has an 'introduction' rule to define it, and hence an 'elimination' rule [Gentzen] |
10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
18852 | A Meinongian principle might say that there is an object for any modest class of properties [Rosen] |
14508 | A 'thisness' is a thing's property of being identical with itself (not the possession of self-identity) [Adams,RM] |
14511 | There are cases where mere qualities would not ensure an intrinsic identity [Adams,RM] |
12031 | Essences are taken to be qualitative properties [Adams,RM] |
12034 | If the universe was cyclical, totally indiscernible events might occur from time to time [Adams,RM] |
14510 | Two events might be indiscernible yet distinct, if there was a universe cyclical in time [Adams,RM] |
16455 | Black's two globes might be one globe in highly curved space [Adams,RM] |
18849 | Metaphysical necessity is absolute and universal; metaphysical possibility is very tolerant [Rosen] |
18850 | 'Metaphysical' modality is the one that makes the necessity or contingency of laws of nature interesting [Rosen] |
18858 | Sets, universals and aggregates may be metaphysically necessary in one sense, but not another [Rosen] |
18857 | Standard Metaphysical Necessity: P holds wherever the actual form of the world holds [Rosen] |
18856 | Non-Standard Metaphysical Necessity: when ¬P is incompatible with the nature of things [Rosen] |
18848 | Something may be necessary because of logic, but is that therefore a special sort of necessity? [Rosen] |
18855 | Combinatorial theories of possibility assume the principles of combination don't change across worlds [Rosen] |
18853 | A proposition is 'correctly' conceivable if an ominiscient being could conceive it [Rosen] |
14507 | Are possible worlds just qualities, or do they include primitive identities as well? [Adams,RM] |
11964 | Possible worlds are world-stories, maximal descriptions of whole non-existent worlds [Adams,RM, by Molnar] |
16451 | Adams says anti-haecceitism reduces all thisness to suchness [Adams,RM, by Stalnaker] |
11901 | Haecceitism may or may not involve some logical connection to essence [Adams,RM, by Mackie,P] |
14512 | Moderate Haecceitism says transworld identities are primitive, but connected to qualities [Adams,RM] |
12032 | Direct reference is by proper names, or indexicals, or referential uses of descriptions [Adams,RM] |
18854 | The MRL view says laws are the theorems of the simplest and strongest account of the world [Rosen] |