63 ideas
16227 | Philosophers are good at denying the obvious [Hawley] |
15924 | Predicative definitions are acceptable in mathematics if they distinguish objects, rather than creating them? [Zermelo, by Lavine] |
10017 | Truth in a model is more tractable than the general notion of truth [Hodes] |
10018 | Truth is quite different in interpreted set theory and in the skeleton of its language [Hodes] |
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] |
10015 | Higher-order logic may be unintelligible, but it isn't set theory [Hodes] |
10011 | Identity is a level one relation with a second-order definition [Hodes] |
16216 | Part of the sense of a proper name is a criterion of the thing's identity [Hawley] |
10016 | When an 'interpretation' creates a model based on truth, this doesn't include Fregean 'sense' [Hodes] |
10027 | Mathematics is higher-order modal logic [Hodes] |
13487 | In ZF, the Burali-Forti Paradox proves that there is no set of all ordinals [Zermelo, by Hart,WD] |
10026 | Arithmetic must allow for the possibility of only a finite total of objects [Hodes] |
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] |
10021 | It is claimed that numbers are objects which essentially represent cardinality quantifiers [Hodes] |
10022 | Numerical terms can't really stand for quantifiers, because that would make them first-level [Hodes] |
16211 | A homogeneous rotating disc should be undetectable according to Humean supervenience [Hawley] |
10023 | Talk of mirror images is 'encoded fictions' about real facts [Hodes] |
16219 | Non-linguistic things cannot be indeterminate, because they don't have truth-values at all [Hawley] |
16223 | Maybe for the world to be vague, it must be vague in its foundations? [Hawley] |
16226 | Epistemic vagueness seems right in the case of persons [Hawley] |
16208 | Supervaluation refers to one vaguely specified thing, through satisfaction by everything in some range [Hawley] |
16221 | Supervaluationism takes what the truth-value would have been if indecision was resolved [Hawley] |
16230 | Maybe the only properties are basic ones like charge, mass and spin [Hawley] |
16232 | An object is 'natural' if its stages are linked by certain non-supervenient relations [Hawley] |
16200 | Are sortals spatially maximal - so no cat part is allowed to be a cat? [Hawley] |
16237 | The modal features of statue and lump are disputed; when does it stop being that statue? [Hawley] |
16238 | Perdurantists can adopt counterpart theory, to explain modal differences of identical part-sums [Hawley] |
16220 | Vagueness is either in our knowledge, in our talk, or in reality [Hawley] |
16222 | Indeterminacy in objects and in properties are not distinct cases [Hawley] |
16228 | The constitution theory is endurantism plus more than one object in a place [Hawley] |
16229 | Constitution theory needs sortal properties like 'being a sweater' to distinguish it from its thread [Hawley] |
14492 | If the constitution view says thread and sweater are two things, why do we talk of one thing? [Hawley] |
16193 | 'Adverbialism' explains change by saying an object has-at-some-time a given property [Hawley] |
16195 | Presentism solves the change problem: the green banana ceases, so can't 'relate' to the yellow one [Hawley] |
16202 | The problem of change arises if there must be 'identity' of a thing over time [Hawley] |
16192 | Endurance theory can relate properties to times, or timed instantiations to properties [Hawley] |
16196 | Endurance is a sophisticated theory, covering properties, instantiation and time [Hawley] |
16197 | How does perdurance theory explain our concern for our own future selves? [Hawley] |
16191 | Perdurance needs an atemporal perspective, to say that the object 'has' different temporal parts [Hawley] |
16199 | If an object is the sum of all of its temporal parts, its mass is staggeringly large! [Hawley] |
16201 | Perdurance says things are sums of stages; Stage Theory says each stage is the thing [Hawley] |
16240 | If a life is essentially the sum of its temporal parts, it couldn't be shorter or longer than it was? [Hawley] |
16203 | Stage Theory seems to miss out the link between stages of the same object [Hawley] |
16204 | Stage Theory says every stage is a distinct object, which gives too many objects [Hawley] |
16212 | An isolated stage can't be a banana (which involves suitable relations to other stages) [Hawley] |
16213 | Stages of one thing are related by extrinsic counterfactual and causal relations [Hawley] |
16205 | The stages of Stage Theory seem too thin to populate the world, or to be referred to [Hawley] |
16206 | Stages must be as fine-grained in length as change itself, so any change is a new stage [Hawley] |
16225 | If two things might be identical, there can't be something true of one and false of the other [Hawley] |
16239 | To decide whether something is a counterpart, we need to specify a relevant sortal concept [Hawley] |
16218 | On any theory of self, it is hard to explain why we should care about our future selves [Hawley] |
16215 | Causation is nothing more than the counterfactuals it grounds? [Hawley] |
16207 | Time could be discrete (like integers) or dense (rationals) or continuous (reals) [Hawley] |