32 ideas
15924 | Predicative definitions are acceptable in mathematics if they distinguish objects, rather than creating them? [Zermelo, by Lavine] |
15063 | Some sentences depend for their truth on worldly circumstances, and others do not [Fine,K] |
17608 | We take set theory as given, and retain everything valuable, while avoiding contradictions [Zermelo] |
17607 | Set theory investigates number, order and function, showing logical foundations for mathematics [Zermelo] |
10870 | ZFC: Existence, Extension, Specification, Pairing, Unions, Powers, Infinity, Choice [Zermelo, by Clegg] |
13012 | Zermelo published his axioms in 1908, to secure a controversial proof [Zermelo, by Maddy] |
17609 | Set theory can be reduced to a few definitions and seven independent axioms [Zermelo] |
13017 | Zermelo introduced Pairing in 1930, and it seems fairly obvious [Zermelo, by Maddy] |
13015 | Zermelo used Foundation to block paradox, but then decided that only Separation was needed [Zermelo, by Maddy] |
13020 | The Axiom of Separation requires set generation up to one step back from contradiction [Zermelo, by Maddy] |
13486 | Not every predicate has an extension, but Separation picks the members that satisfy a predicate [Zermelo, by Hart,WD] |
13487 | In ZF, the Burali-Forti Paradox proves that there is no set of all ordinals [Zermelo, by Hart,WD] |
18178 | For Zermelo the successor of n is {n} (rather than n U {n}) [Zermelo, by Maddy] |
13027 | Zermelo believed, and Von Neumann seemed to confirm, that numbers are sets [Zermelo, by Maddy] |
9627 | Different versions of set theory result in different underlying structures for numbers [Zermelo, by Brown,JR] |
15078 | There are levels of existence, as well as reality; objects exist at the lowest level in which they can function [Fine,K] |
15072 | Bottom level facts are subject to time and world, middle to world but not time, and top to neither [Fine,K] |
15071 | Tensed and tenseless sentences state two sorts of fact, which belong to two different 'realms' of reality [Fine,K] |
15075 | Modal features are not part of entities, because they are accounted for by the entity [Fine,K] |
15065 | What it is is fixed prior to existence or the object's worldly features [Fine,K] |
15076 | Essential features of an object have no relation to how things actually are [Fine,K] |
15073 | Self-identity should have two components, its existence, and its neutral identity with itself [Fine,K] |
15074 | We would understand identity between objects, even if their existence was impossible [Fine,K] |
15064 | Proper necessary truths hold whatever the circumstances; transcendent truths regardless of circumstances [Fine,K] |
15070 | It is the nature of Socrates to be a man, so necessarily he is a man [Fine,K] |
15069 | Possible worlds may be more limited, to how things might actually turn out [Fine,K] |
15068 | The actual world is a totality of facts, so we also think of possible worlds as totalities [Fine,K] |
19696 | There are reasons 'for which' a belief is held, reasons 'why' it is believed, and reasons 'to' believe it [Neta] |
19697 | The basing relation of a reason to a belief should both support and explain the belief [Neta] |
15067 | A-theorists tend to reject the tensed/tenseless distinction [Fine,K] |
15077 | It is said that in the A-theory, all existents and objects must be tensed, as well as the sentences [Fine,K] |
15066 | B-theorists say tensed sentences have an unfilled argument-place for a time [Fine,K] |