Combining Texts

All the ideas for 'fragments/reports', 'Thinking About Logic' and 'Knowledge by Agreement'

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72 ideas

3. Truth / C. Correspondence Truth / 1. Correspondence Truth
Correspondence could be with other beliefs, rather than external facts [Kusch]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
Tarskians distinguish truth from falsehood by relations between members of sets [Kusch]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / c. Derivation rules of PL
Three traditional names of rules are 'Simplification', 'Addition' and 'Disjunctive Syllogism' [Read]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / a. Systems of modal logic
Necessity is provability in S4, and true in all worlds in S5 [Read]
4. Formal Logic / E. Nonclassical Logics / 4. Fuzzy Logic
There are fuzzy predicates (and sets), and fuzzy quantifiers and modifiers [Read]
4. Formal Logic / E. Nonclassical Logics / 6. Free Logic
Same say there are positive, negative and neuter free logics [Read]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / c. Logical sets
Realisms like the full Comprehension Principle, that all good concepts determine sets [Read]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Not all validity is captured in first-order logic [Read]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
The non-emptiness of the domain is characteristic of classical logic [Read]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Semantics must precede proof in higher-order logics, since they are incomplete [Read]
5. Theory of Logic / A. Overview of Logic / 8. Logic of Mathematics
We should exclude second-order logic, precisely because it captures arithmetic [Read]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
A theory of logical consequence is a conceptual analysis, and a set of validity techniques [Read]
Logical consequence isn't just a matter of form; it depends on connections like round-square [Read]
5. Theory of Logic / E. Structures of Logic / 8. Theories in Logic
A theory is logically closed, which means infinite premisses [Read]
5. Theory of Logic / G. Quantification / 1. Quantification
Quantifiers are second-order predicates [Read]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
In second-order logic the higher-order variables range over all the properties of the objects [Read]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
A logical truth is the conclusion of a valid inference with no premisses [Read]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Any first-order theory of sets is inadequate [Read]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Compactness is when any consequence of infinite propositions is the consequence of a finite subset [Read]
Compactness does not deny that an inference can have infinitely many premisses [Read]
Compactness blocks the proof of 'for every n, A(n)' (as the proof would be infinite) [Read]
Compactness makes consequence manageable, but restricts expressive power [Read]
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
Self-reference paradoxes seem to arise only when falsity is involved [Read]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite
Infinite cuts and successors seems to suggest an actual infinity there waiting for us [Read]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Although second-order arithmetic is incomplete, it can fully model normal arithmetic [Read]
Second-order arithmetic covers all properties, ensuring categoricity [Read]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / g. Von Neumann numbers
Von Neumann numbers are helpful, but don't correctly describe numbers [Read]
7. Existence / D. Theories of Reality / 10. Vagueness / d. Vagueness as linguistic
Would a language without vagueness be usable at all? [Read]
7. Existence / D. Theories of Reality / 10. Vagueness / f. Supervaluation for vagueness
Supervaluations say there is a cut-off somewhere, but at no particular place [Read]
A 'supervaluation' gives a proposition consistent truth-value for classical assignments [Read]
Identities and the Indiscernibility of Identicals don't work with supervaluations [Read]
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
A haecceity is a set of individual properties, essential to each thing [Read]
10. Modality / A. Necessity / 2. Nature of Necessity
Equating necessity with truth in every possible world is the S5 conception of necessity [Read]
10. Modality / B. Possibility / 8. Conditionals / a. Conditionals
The point of conditionals is to show that one will accept modus ponens [Read]
The standard view of conditionals is that they are truth-functional [Read]
Some people even claim that conditionals do not express propositions [Read]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
Knowledge of possible worlds is not causal, but is an ontology entailed by semantics [Read]
10. Modality / E. Possible worlds / 1. Possible Worlds / c. Possible worlds realism
How can modal Platonists know the truth of a modal proposition? [Read]
10. Modality / E. Possible worlds / 1. Possible Worlds / d. Possible worlds actualism
Actualism is reductionist (to parts of actuality), or moderate realist (accepting real abstractions) [Read]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / c. Worlds as propositions
A possible world is a determination of the truth-values of all propositions of a domain [Read]
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
If worlds are concrete, objects can't be present in more than one, and can only have counterparts [Read]
11. Knowledge Aims / A. Knowledge / 4. Belief / a. Beliefs
We can have knowledge without belief, if others credit us with knowledge [Kusch]
11. Knowledge Aims / C. Knowing Reality / 4. Solipsism
Methodological Solipsism assumes all ideas could be derived from one mind [Kusch]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / f. Foundationalism critique
Foundations seem utterly private, even from oneself at a later time [Kusch]
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / a. Coherence as justification
Testimony is reliable if it coheres with evidence for a belief, and with other beliefs [Kusch]
The coherentist restricts the space of reasons to the realm of beliefs [Kusch]
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / c. Coherentism critique
Individualistic coherentism lacks access to all of my beliefs, or critical judgement of my assessment [Kusch]
Individual coherentism cannot generate the necessary normativity [Kusch]
13. Knowledge Criteria / C. External Justification / 2. Causal Justification
Cultures decide causal routes, and they can be critically assessed [Kusch]
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / a. Reliable knowledge
Process reliabilism has been called 'virtue epistemology', resting on perception, memory, reason [Kusch]
13. Knowledge Criteria / C. External Justification / 6. Contextual Justification / a. Contextualism
Justification depends on the audience and one's social role [Kusch]
13. Knowledge Criteria / C. External Justification / 7. Testimony
Testimony is an area in which epistemology meets ethics [Kusch]
Powerless people are assumed to be unreliable, even about their own lives [Kusch]
Testimony does not just transmit knowledge between individuals - it actually generates knowledge [Kusch]
Some want to reduce testimony to foundations of perceptions, memories and inferences [Kusch]
Testimony won't reduce to perception, if perception depends on social concepts and categories [Kusch]
A foundation is what is intelligible, hence from a rational source, and tending towards truth [Kusch]
Vindicating testimony is an expression of individualism [Kusch]
13. Knowledge Criteria / C. External Justification / 8. Social Justification
Myths about lonely genius are based on epistemological individualism [Kusch]
Communitarian Epistemology says 'knowledge' is a social status granted to groups of people [Kusch]
Private justification is justification to imagined other people [Kusch]
15. Nature of Minds / C. Capacities of Minds / 3. Abstraction by mind
The mind abstracts ways things might be, which are nonetheless real [Read]
16. Persons / E. Rejecting the Self / 2. Self as Social Construct
To be considered 'an individual' is performed by a society [Kusch]
18. Thought / D. Concepts / 1. Concepts / a. Nature of concepts
Our experience may be conceptual, but surely not the world itself? [Kusch]
19. Language / C. Assigning Meanings / 4. Compositionality
Negative existentials with compositionality make the whole sentence meaningless [Read]
19. Language / D. Propositions / 1. Propositions
A proposition objectifies what a sentence says, as indicative, with secure references [Read]
19. Language / F. Communication / 1. Rhetoric
Often socialising people is the only way to persuade them [Kusch]
24. Political Theory / D. Ideologies / 7. Communitarianism / a. Communitarianism
Communitarianism in epistemology sees the community as the primary knower [Kusch]
26. Natural Theory / A. Speculations on Nature / 5. Infinite in Nature
Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius]
26. Natural Theory / B. Natural Kinds / 7. Critique of Kinds
Natural kinds are social institutions [Kusch]
27. Natural Reality / G. Biology / 3. Evolution
Archelaus said life began in a primeval slime [Archelaus, by Schofield]
28. God / A. Divine Nature / 4. Divine Contradictions
Omniscience is incoherent, since knowledge is a social concept [Kusch]