Combining Texts

All the ideas for 'Logicism and Ontological Commits. of Arithmetic', 'How Things Persist' and 'Investigations in the Foundations of Set Theory I'

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63 ideas

1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
Philosophers are good at denying the obvious [Hawley]
2. Reason / D. Definition / 8. Impredicative Definition
Predicative definitions are acceptable in mathematics if they distinguish objects, rather than creating them? [Zermelo, by Lavine]
3. Truth / F. Semantic Truth / 2. Semantic Truth
Truth in a model is more tractable than the general notion of truth [Hodes]
Truth is quite different in interpreted set theory and in the skeleton of its language [Hodes]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
We take set theory as given, and retain everything valuable, while avoiding contradictions [Zermelo]
Set theory investigates number, order and function, showing logical foundations for mathematics [Zermelo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
ZFC: Existence, Extension, Specification, Pairing, Unions, Powers, Infinity, Choice [Zermelo, by Clegg]
Zermelo published his axioms in 1908, to secure a controversial proof [Zermelo, by Maddy]
Set theory can be reduced to a few definitions and seven independent axioms [Zermelo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / c. Axiom of Pairing II
Zermelo introduced Pairing in 1930, and it seems fairly obvious [Zermelo, by Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / i. Axiom of Foundation VIII
Zermelo used Foundation to block paradox, but then decided that only Separation was needed [Zermelo, by Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / m. Axiom of Separation
The Axiom of Separation requires set generation up to one step back from contradiction [Zermelo, by Maddy]
Not every predicate has an extension, but Separation picks the members that satisfy a predicate [Zermelo, by Hart,WD]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Higher-order logic may be unintelligible, but it isn't set theory [Hodes]
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
Identity is a level one relation with a second-order definition [Hodes]
5. Theory of Logic / F. Referring in Logic / 1. Naming / b. Names as descriptive
Part of the sense of a proper name is a criterion of the thing's identity [Hawley]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
When an 'interpretation' creates a model based on truth, this doesn't include Fregean 'sense' [Hodes]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / a. Numbers
Mathematics is higher-order modal logic [Hodes]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
In ZF, the Burali-Forti Paradox proves that there is no set of all ordinals [Zermelo, by Hart,WD]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / f. Arithmetic
Arithmetic must allow for the possibility of only a finite total of objects [Hodes]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / f. Zermelo numbers
For Zermelo the successor of n is {n} (rather than n U {n}) [Zermelo, by Maddy]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Zermelo believed, and Von Neumann seemed to confirm, that numbers are sets [Zermelo, by Maddy]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
Different versions of set theory result in different underlying structures for numbers [Zermelo, by Brown,JR]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
It is claimed that numbers are objects which essentially represent cardinality quantifiers [Hodes]
Numerical terms can't really stand for quantifiers, because that would make them first-level [Hodes]
7. Existence / C. Structure of Existence / 5. Supervenience / d. Humean supervenience
A homogeneous rotating disc should be undetectable according to Humean supervenience [Hawley]
7. Existence / D. Theories of Reality / 7. Fictionalism
Talk of mirror images is 'encoded fictions' about real facts [Hodes]
7. Existence / D. Theories of Reality / 10. Vagueness / b. Vagueness of reality
Non-linguistic things cannot be indeterminate, because they don't have truth-values at all [Hawley]
Maybe for the world to be vague, it must be vague in its foundations? [Hawley]
7. Existence / D. Theories of Reality / 10. Vagueness / c. Vagueness as ignorance
Epistemic vagueness seems right in the case of persons [Hawley]
7. Existence / D. Theories of Reality / 10. Vagueness / f. Supervaluation for vagueness
Supervaluation refers to one vaguely specified thing, through satisfaction by everything in some range [Hawley]
Supervaluationism takes what the truth-value would have been if indecision was resolved [Hawley]
8. Modes of Existence / B. Properties / 1. Nature of Properties
Maybe the only properties are basic ones like charge, mass and spin [Hawley]
9. Objects / A. Existence of Objects / 1. Physical Objects
An object is 'natural' if its stages are linked by certain non-supervenient relations [Hawley]
9. Objects / B. Unity of Objects / 3. Unity Problems / b. Cat and its tail
Are sortals spatially maximal - so no cat part is allowed to be a cat? [Hawley]
9. Objects / B. Unity of Objects / 3. Unity Problems / c. Statue and clay
The modal features of statue and lump are disputed; when does it stop being that statue? [Hawley]
Perdurantists can adopt counterpart theory, to explain modal differences of identical part-sums [Hawley]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
Vagueness is either in our knowledge, in our talk, or in reality [Hawley]
Indeterminacy in objects and in properties are not distinct cases [Hawley]
9. Objects / C. Structure of Objects / 6. Constitution of an Object
The constitution theory is endurantism plus more than one object in a place [Hawley]
Constitution theory needs sortal properties like 'being a sweater' to distinguish it from its thread [Hawley]
If the constitution view says thread and sweater are two things, why do we talk of one thing? [Hawley]
9. Objects / E. Objects over Time / 2. Objects that Change
'Adverbialism' explains change by saying an object has-at-some-time a given property [Hawley]
Presentism solves the change problem: the green banana ceases, so can't 'relate' to the yellow one [Hawley]
The problem of change arises if there must be 'identity' of a thing over time [Hawley]
9. Objects / E. Objects over Time / 3. Three-Dimensionalism
Endurance theory can relate properties to times, or timed instantiations to properties [Hawley]
Endurance is a sophisticated theory, covering properties, instantiation and time [Hawley]
9. Objects / E. Objects over Time / 4. Four-Dimensionalism
How does perdurance theory explain our concern for our own future selves? [Hawley]
Perdurance needs an atemporal perspective, to say that the object 'has' different temporal parts [Hawley]
If an object is the sum of all of its temporal parts, its mass is staggeringly large! [Hawley]
Perdurance says things are sums of stages; Stage Theory says each stage is the thing [Hawley]
If a life is essentially the sum of its temporal parts, it couldn't be shorter or longer than it was? [Hawley]
9. Objects / E. Objects over Time / 5. Temporal Parts
Stage Theory seems to miss out the link between stages of the same object [Hawley]
Stage Theory says every stage is a distinct object, which gives too many objects [Hawley]
An isolated stage can't be a banana (which involves suitable relations to other stages) [Hawley]
Stages of one thing are related by extrinsic counterfactual and causal relations [Hawley]
The stages of Stage Theory seem too thin to populate the world, or to be referred to [Hawley]
Stages must be as fine-grained in length as change itself, so any change is a new stage [Hawley]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
If two things might be identical, there can't be something true of one and false of the other [Hawley]
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
To decide whether something is a counterpart, we need to specify a relevant sortal concept [Hawley]
16. Persons / D. Continuity of the Self / 5. Concerns of the Self
On any theory of self, it is hard to explain why we should care about our future selves [Hawley]
26. Natural Theory / C. Causation / 9. General Causation / c. Counterfactual causation
Causation is nothing more than the counterfactuals it grounds? [Hawley]
27. Natural Reality / D. Time / 3. Parts of Time / b. Instants
Time could be discrete (like integers) or dense (rationals) or continuous (reals) [Hawley]