Combining Philosophers

All the ideas for Jonathan Dancy, Richard Jeffrey and John P. Burgess

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93 ideas

1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
As coherence expands its interrelations become steadily tighter, culminating only in necessary truth [Dancy,J]
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
The correspondence theory also has the problem that two sets of propositions might fit the facts equally well [Dancy,J]
3. Truth / D. Coherence Truth / 1. Coherence Truth
Rescher says that if coherence requires mutual entailment, this leads to massive logical redundancy [Dancy,J]
If one theory is held to be true, all the other theories appear false, because they can't be added to the true one [Dancy,J]
3. Truth / D. Coherence Truth / 2. Coherence Truth Critique
Even with a tight account of coherence, there is always the possibility of more than one set of coherent propositions [Dancy,J]
4. Formal Logic / D. Modal Logic ML / 6. Temporal Logic
With four tense operators, all complex tenses reduce to fourteen basic cases [Burgess]
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
The temporal Barcan formulas fix what exists, which seems absurd [Burgess]
4. Formal Logic / E. Nonclassical Logics / 2. Intuitionist Logic
Is classical logic a part of intuitionist logic, or vice versa? [Burgess]
It is still unsettled whether standard intuitionist logic is complete [Burgess]
4. Formal Logic / E. Nonclassical Logics / 5. Relevant Logic
Relevance logic's → is perhaps expressible by 'if A, then B, for that reason' [Burgess]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
Technical people see logic as any formal system that can be studied, not a study of argument validity [Burgess]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Classical logic neglects the non-mathematical, such as temporality or modality [Burgess]
The Cut Rule expresses the classical idea that entailment is transitive [Burgess]
Classical logic neglects counterfactuals, temporality and modality, because maths doesn't use them [Burgess]
5. Theory of Logic / A. Overview of Logic / 9. Philosophical Logic
Philosophical logic is a branch of logic, and is now centred in computer science [Burgess]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
Formalising arguments favours lots of connectives; proving things favours having very few [Burgess]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / e. or
Asserting a disjunction from one disjunct seems odd, but can be sensible, and needed in maths [Burgess]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
All occurrences of variables in atomic formulas are free [Burgess]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / b. Definite descriptions
The denotation of a definite description is flexible, rather than rigid [Burgess]
5. Theory of Logic / H. Proof Systems / 1. Proof Systems
'Induction' and 'recursion' on complexity prove by connecting a formula to its atomic components [Burgess]
5. Theory of Logic / H. Proof Systems / 6. Sequent Calculi
The sequent calculus makes it possible to have proof without transitivity of entailment [Burgess]
We can build one expanding sequence, instead of a chain of deductions [Burgess]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
'Tautologies' are valid formulas of classical sentential logic - or substitution instances in other logics [Burgess]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
Validity (for truth) and demonstrability (for proof) have correlates in satisfiability and consistency [Burgess]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Models leave out meaning, and just focus on truth values [Burgess]
We only need to study mathematical models, since all other models are isomorphic to these [Burgess]
We aim to get the technical notion of truth in all models matching intuitive truth in all instances [Burgess]
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
The Liar seems like a truth-value 'gap', but dialethists see it as a 'glut' [Burgess]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Set theory is the standard background for modern mathematics [Burgess]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Structuralists take the name 'R' of the reals to be a variable ranging over structures, not a structure [Burgess]
There is no one relation for the real number 2, as relations differ in different models [Burgess]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
If set theory is used to define 'structure', we can't define set theory structurally [Burgess]
Abstract algebra concerns relations between models, not common features of all the models [Burgess]
How can mathematical relations be either internal, or external, or intrinsic? [Burgess]
7. Existence / D. Theories of Reality / 2. Realism
Realism says that most perceived objects exist, and have some of their perceived properties [Dancy,J]
10. Modality / A. Necessity / 4. De re / De dicto modality
De re modality seems to apply to objects a concept intended for sentences [Burgess]
10. Modality / A. Necessity / 6. Logical Necessity
General consensus is S5 for logical modality of validity, and S4 for proof [Burgess]
Logical necessity has two sides - validity and demonstrability - which coincide in classical logic [Burgess]
10. Modality / B. Possibility / 8. Conditionals / a. Conditionals
Three conditionals theories: Materialism (material conditional), Idealism (true=assertable), Nihilism (no truth) [Burgess]
It is doubtful whether the negation of a conditional has any clear meaning [Burgess]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / b. Worlds as fictions
A possible world can be seen as a complete and consistent novel [Jeffrey]
11. Knowledge Aims / B. Certain Knowledge / 1. Certainty
A pupil who lacks confidence may clearly know something but not be certain of it [Dancy,J]
11. Knowledge Aims / B. Certain Knowledge / 3. Fallibilism
If senses are fallible, then being open to correction is an epistemological virtue [Dancy,J]
11. Knowledge Aims / C. Knowing Reality / 1. Perceptual Realism / a. Naïve realism
Naïve direct realists hold that objects retain all of their properties when unperceived [Dancy,J]
11. Knowledge Aims / C. Knowing Reality / 1. Perceptual Realism / b. Direct realism
Scientific direct realism says we know some properties of objects directly [Dancy,J]
Maybe we are forced from direct into indirect realism by the need to explain perceptual error [Dancy,J]
11. Knowledge Aims / C. Knowing Reality / 1. Perceptual Realism / c. Representative realism
Internal realism holds that we perceive physical objects via mental objects [Dancy,J]
Indirect realism depends on introspection, the time-lag, illusions, and neuroscience [Dancy,J, by PG]
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
Phenomenalism includes possible experiences, but idealism only refers to actual experiences [Dancy,J]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / a. Idealism
Eliminative idealists say there are no objects; reductive idealists say objects exist as complex experiences [Dancy,J]
11. Knowledge Aims / C. Knowing Reality / 4. Solipsism
Extreme solipsism only concerns current experience, but it might include past and future [Dancy,J]
12. Knowledge Sources / A. A Priori Knowledge / 5. A Priori Synthetic
Knowing that a cow is not a horse seems to be a synthetic a priori truth [Dancy,J]
12. Knowledge Sources / B. Perception / 1. Perception
Perception is either direct realism, indirect realism, or phenomenalism [Dancy,J]
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / e. Primary/secondary critique
We can't grasp the separation of quality types, or what a primary-quality world would be like [Dancy,J]
For direct realists the secondary and primary qualities seem equally direct [Dancy,J]
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
We can be looking at distant stars which no longer actually exist [Dancy,J]
12. Knowledge Sources / B. Perception / 4. Sense Data / b. Nature of sense-data
It is not clear from the nature of sense data whether we should accept them as facts [Dancy,J]
12. Knowledge Sources / B. Perception / 7. Causal Perception
Appearances don't guarantee reality, unless the appearance is actually caused by the reality [Dancy,J]
Perceptual beliefs may be directly caused, but generalisations can't be [Dancy,J]
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
If perception and memory are indirect, then two things stand between mind and reality [Dancy,J]
Memories aren't directly about the past, because time-lags and illusions suggest representation [Dancy,J]
Phenomenalism about memory denies the past, or reduces it to present experience [Dancy,J]
I can remember plans about the future, and images aren't essential (2+3=5) [Dancy,J]
13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / a. Agrippa's trilemma
Foundations are justified by non-beliefs, or circularly, or they need no justification [Dancy,J]
13. Knowledge Criteria / A. Justification Problems / 3. Internal or External / a. Pro-internalism
For internalists we must actually know that the fact caused the belief [Dancy,J]
Internalists tend to favour coherent justification, but not the coherence theory of truth [Dancy,J]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / a. Foundationalism
Foundationalism requires inferential and non-inferential justification [Dancy,J]
Foundationalists must accept not only the basic beliefs, but also rules of inference for further progress [Dancy,J]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / b. Basic beliefs
If basic beliefs can be false, falsehood in non-basic beliefs might by a symptom [Dancy,J]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / f. Foundationalism critique
Beliefs can only be infallible by having almost no content [Dancy,J]
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / a. Coherence as justification
Coherentism gives a possible justification of induction, and opposes scepticism [Dancy,J]
Idealists must be coherentists, but coherentists needn't be idealists [Dancy,J]
For coherentists justification and truth are not radically different things [Dancy,J]
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / b. Pro-coherentism
If it is empirical propositions which have to be coherent, this eliminates coherent fiction [Dancy,J]
13. Knowledge Criteria / C. External Justification / 1. External Justification
Externalism could even make belief unnecessary (e.g. in animals) [Dancy,J]
13. Knowledge Criteria / C. External Justification / 2. Causal Justification
How can a causal theory of justification show that all men die? [Dancy,J]
Causal theories don't allow for errors in justification [Dancy,J]
13. Knowledge Criteria / C. External Justification / 8. Social Justification
Coherentism moves us towards a more social, shared view of knowledge [Dancy,J]
13. Knowledge Criteria / D. Scepticism / 6. Scepticism Critique
What is the point of arguing against knowledge, if being right undermines your own argument? [Dancy,J]
14. Science / C. Induction / 6. Bayes's Theorem
Probabilities can only be assessed relative to some evidence [Dancy,J]
Instead of gambling, Jeffrey made the objects of Bayesian preference to be propositions [Jeffrey, by Davidson]
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / d. Other minds by analogy
The argument from analogy rests on one instance alone [Dancy,J]
You can't separate mind and behaviour, as the analogy argument attempts [Dancy,J]
19. Language / A. Nature of Meaning / 5. Meaning as Verification
Verificationism (the 'verification principle') is an earlier form of anti-realism [Dancy,J]
Logical positivism implies foundationalism, by dividing weak from strong verifications [Dancy,J]
19. Language / A. Nature of Meaning / 7. Meaning Holism / b. Language holism
If the meanings of sentences depend on other sentences, how did we learn language? [Dancy,J]
19. Language / F. Communication / 6. Interpreting Language / b. Indeterminate translation
There is an indeterminacy in juggling apparent meanings against probable beliefs [Dancy,J]
19. Language / F. Communication / 6. Interpreting Language / c. Principle of charity
Charity makes native beliefs largely true, and Humanity makes them similar to ours [Dancy,J]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
If there are intuited moral facts, why should we care about them? [Dancy,J]
Internalists say that moral intuitions are motivating; externalist say a desire is also needed [Dancy,J]
Obviously judging an action as wrong gives us a reason not to do it [Dancy,J]
Moral facts are not perceived facts, but perceived reasons for judgements [Dancy,J]
22. Metaethics / B. Value / 1. Nature of Value / a. Nature of value
The base for values has grounds, catalysts and intensifiers [Dancy,J, by Orsi]