Combining Texts

All the ideas for 'Mathematical Methods in Philosophy', 'works' and 'Evidence'

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25 ideas

2. Reason / A. Nature of Reason / 1. On Reason
For clear questions posed by reason, reason can also find clear answers [Gödel]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Gödel proved that first-order logic is complete, and second-order logic incomplete [Gödel, by Dummett]
5. Theory of Logic / A. Overview of Logic / 9. Philosophical Logic
Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew]
5. Theory of Logic / I. Semantics of Logic / 2. Formal Truth
Originally truth was viewed with total suspicion, and only demonstrability was accepted [Gödel]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
Gödel's Theorems did not refute the claim that all good mathematical questions have answers [Gödel, by Koellner]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
Gödel eventually hoped for a generalised completeness theorem leaving nothing undecidable [Gödel, by Koellner]
The real reason for Incompleteness in arithmetic is inability to define truth in a language [Gödel]
7. Existence / A. Nature of Existence / 1. Nature of Existence
If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew]
The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew]
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
Epistemic logic introduced impossible worlds [Horsten/Pettigrew]
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew]
Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew]
13. Knowledge Criteria / A. Justification Problems / 3. Internal or External / a. Pro-internalism
Internalists are much more interested in evidence than externalists are [McGrew]
13. Knowledge Criteria / B. Internal Justification / 3. Evidentialism / a. Evidence
Does spotting a new possibility count as evidence? [McGrew]
Absence of evidence proves nothing, and weird claims need special evidence [McGrew]
Every event is highly unlikely (in detail), but may be perfectly plausible [McGrew]
Criminal law needs two separate witnesses, but historians will accept one witness [McGrew]
Maybe all evidence consists of beliefs, rather than of facts [McGrew]
If all evidence is propositional, what is the evidence for the proposition? Do we face a regress? [McGrew]
Several unreliable witnesses can give good support, if they all say the same thing [McGrew]
13. Knowledge Criteria / B. Internal Justification / 3. Evidentialism / b. Evidentialism
Narrow evidentialism relies wholly on propositions; the wider form includes other items [McGrew]
14. Science / A. Basis of Science / 6. Falsification
Falsificationism would be naive if even a slight discrepancy in evidence killed a theory [McGrew]