33 ideas
19275 | You cannot understand what exists without understanding possibility and necessity [Hale] |
19291 | A canonical defintion specifies the type of thing, and what distinguish this specimen [Hale] |
19297 | The two Barcan principles are easily proved in fairly basic modal logic [Hale] |
19301 | With a negative free logic, we can dispense with the Barcan formulae [Hale] |
19296 | If second-order variables range over sets, those are just objects; properties and relations aren't sets [Hale] |
18739 | Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew] |
19289 | Maybe conventionalism applies to meaning, but not to the truth of propositions expressed [Hale] |
18741 | Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew] |
19298 | Unlike axiom proofs, natural deduction proofs needn't focus on logical truths and theorems [Hale] |
18744 | Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew] |
19295 | Add Hume's principle to logic, to get numbers; arithmetic truths rest on the nature of the numbers [Hale] |
18740 | If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew] |
19281 | Interesting supervenience must characterise the base quite differently from what supervenes on it [Hale] |
19278 | There is no gap between a fact that p, and it is true that p; so we only have the truth-condtions for p [Hale] |
19302 | If a chair could be made of slightly different material, that could lead to big changes [Hale] |
19290 | Absolute necessities are necessarily necessary [Hale] |
19286 | 'Absolute necessity' is when there is no restriction on the things which necessitate p [Hale] |
19288 | Logical and metaphysical necessities differ in their vocabulary, and their underlying entities [Hale] |
19285 | Logical necessity is something which is true, no matter what else is the case [Hale] |
19287 | Maybe each type of logic has its own necessity, gradually becoming broader [Hale] |
19282 | It seems that we cannot show that modal facts depend on non-modal facts [Hale] |
19276 | The big challenge for essentialist views of modality is things having necessary existence [Hale] |
19293 | Essentialism doesn't explain necessity reductively; it explains all necessities in terms of a few basic natures [Hale] |
19294 | If necessity derives from essences, how do we explain the necessary existence of essences? [Hale] |
19279 | What are these worlds, that being true in all of them makes something necessary? [Hale] |
18745 | A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew] |
18747 | The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew] |
18748 | Epistemic logic introduced impossible worlds [Horsten/Pettigrew] |
19299 | Possible worlds make every proposition true or false, which endorses classical logic [Hale] |
18746 | Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew] |
18750 | Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew] |
19300 | The molecules may explain the water, but they are not what 'water' means [Hale] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |