display all the ideas for this combination of philosophers
4 ideas
19033 | Deontic modalities are 'ought-to-be', for sentences, and 'ought-to-do' for predicates [Vetter] |
Full Idea: Deontic modality can be divided into sentence-modifying 'ought-to-be' modals, and predicate-modifying 'ought-to-do' modals. | |
From: Barbara Vetter (Potentiality [2015], 6.9.2) | |
A reaction: [She cites Brennan 1993] These two seem to correspond to what is 'good' (ought to be), and what is 'right' (ought to do). Since I like that distinction, I also like this one. |
19032 | S5 is undesirable, as it prevents necessities from having contingent grounds [Vetter] |
Full Idea: Wedgwood (2007:220) argues that S5 is undesirable because it excludes that necessary truths may have contingent grounds. | |
From: Barbara Vetter (Potentiality [2015], 6.4 n5) | |
A reaction: Cameron defends the possibility of necessity grounded in contingency, against Blackburn's denial of it. It's interesting that we choose the logic on the basis of the metaphysics. Shouldn't there be internal reasons for a logic's correctness? |
19036 | The Barcan formula endorses either merely possible things, or makes the unactualised impossible [Vetter] |
Full Idea: Subscribers to the Barcan formula must either be committed to the existence of mere possibilia (such as possible unicorns), or deny many unactualised possibilities of existence. | |
From: Barbara Vetter (Potentiality [2015], 7.5) | |
A reaction: It increasingly strikes me that the implications of the Barcan formula are ridiculous. Williamson is its champion, but I'm blowed if I can see why. What could a possible unicorn be like? Without them, must we say unicorns are impossible? |
8920 | Equivalence relations are reflexive, symmetric and transitive, and classify similar objects [Lipschutz] |
Full Idea: A relation R on a non-empty set S is an equivalence relation if it is reflexive (for each member a, aRa), symmetric (if aRb, then bRa), and transitive (aRb and bRc, so aRc). It tries to classify objects that are in some way 'alike'. | |
From: Seymour Lipschutz (Set Theory and related topics (2nd ed) [1998], 3.9) | |
A reaction: So this is an attempt to formalise the common sense notion of seeing that two things have something in common. Presumably a 'way' of being alike is going to be a property or a part |