20 ideas
11064 | Classes can be reduced to propositional functions [Russell, by Hanna] |
13010 | In order to select the logic justified by experience, we would need to use a lot of logic [Boghossian on Quine] |
9002 | Elementary logic requires truth-functions, quantifiers (and variables), identity, and also sets of variables [Quine] |
13681 | Logical consequence is marked by being preserved under all nonlogical substitutions [Quine, by Sider] |
13829 | If logical truths essentially depend on logical constants, we had better define the latter [Hacking on Quine] |
9003 | Set theory was struggling with higher infinities, when new paradoxes made it baffling [Quine] |
6407 | The class of classes which lack self-membership leads to a contradiction [Russell, by Grayling] |
10418 | Type theory seems an extreme reaction, since self-exemplification is often innocuous [Swoyer on Russell] |
10047 | Russell's improvements blocked mathematics as well as paradoxes, and needed further axioms [Russell, by Musgrave] |
23478 | Type theory means that features shared by different levels cannot be expressed [Morris,M on Russell] |
21718 | Ramified types can be defended as a system of intensional logic, with a 'no class' view of sets [Russell, by Linsky,B] |
9004 | If set theory is not actually a branch of logic, then Frege's derivation of arithmetic would not be from logic [Quine] |
18126 | A set does not exist unless at least one of its specifications is predicative [Russell, by Bostock] |
18128 | Russell is a conceptualist here, saying some abstracta only exist because definitions create them [Russell, by Bostock] |
18124 | Vicious Circle says if it is expressed using the whole collection, it can't be in the collection [Russell, by Bostock] |
9006 | Commitment to universals is as arbitrary or pragmatic as the adoption of a new system of bookkeeping [Quine] |
9001 | Frege moved Kant's question about a priori synthetic to 'how is logical certainty possible?' [Quine] |
12739 | If we are dreaming, it is sufficient that the events are coherent, and obey laws [Leibniz] |
9005 | Examination of convention in the a priori begins to blur the distinction with empirical knowledge [Quine] |
12738 | Successful prediction shows proficiency in nature [Leibniz] |