Combining Philosophers

All the ideas for Alfred Tarski, Agrippa and Jonathan Schaffer

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139 ideas

1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Modern Quinean metaphysics is about what exists, but Aristotelian metaphysics asks about grounding [Schaffer,J]
1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
If you tore the metaphysics out of philosophy, the whole enterprise would collapse [Schaffer,J]
1. Philosophy / E. Nature of Metaphysics / 5. Metaphysics beyond Science
Some say metaphysics is a highly generalised empirical study of objects [Tarski]
1. Philosophy / F. Analytic Philosophy / 1. Nature of Analysis
Disputes that fail to use precise scientific terminology are all meaningless [Tarski]
1. Philosophy / F. Analytic Philosophy / 3. Analysis of Preconditions
Analysis aims at secure necessary and sufficient conditions [Schaffer,J]
2. Reason / A. Nature of Reason / 9. Limits of Reason
Reasoning needs arbitrary faith in preliminary hypotheses (Mode 14) [Agrippa, by Diog. Laertius]
All discussion is full of uncertainty and contradiction (Mode 11) [Agrippa, by Diog. Laertius]
All reasoning endlessly leads to further reasoning (Mode 12) [Agrippa, by Diog. Laertius]
Proofs often presuppose the thing to be proved (Mode 15) [Agrippa, by Diog. Laertius]
2. Reason / B. Laws of Thought / 6. Ockham's Razor
We should not multiply basic entities, but we can have as many derivative entities as we like [Schaffer,J]
2. Reason / D. Definition / 1. Definitions
For a definition we need the words or concepts used, the rules, and the structure of the language [Tarski]
2. Reason / F. Fallacies / 1. Fallacy
'Reification' occurs if we mistake a concept for a thing [Schaffer,J]
3. Truth / A. Truth Problems / 2. Defining Truth
Tarski proved that truth cannot be defined from within a given theory [Tarski, by Halbach]
Tarski proved that any reasonably expressive language suffers from the liar paradox [Tarski, by Horsten]
'True sentence' has no use consistent with logic and ordinary language, so definition seems hopeless [Tarski]
In everyday language, truth seems indefinable, inconsistent, and illogical [Tarski]
Definitions of truth should not introduce a new version of the concept, but capture the old one [Tarski]
A definition of truth should be materially adequate and formally correct [Tarski]
A rigorous definition of truth is only possible in an exactly specified language [Tarski]
We may eventually need to split the word 'true' into several less ambiguous terms [Tarski]
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
Tarski's Theorem renders any precise version of correspondence impossible [Tarski, by Halbach]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / a. Tarski's truth definition
Tarskian semantics says that a sentence is true iff it is satisfied by every sequence [Tarski, by Hossack]
'"It is snowing" is true if and only if it is snowing' is a partial definition of the concept of truth [Tarski]
It is convenient to attach 'true' to sentences, and hence the language must be specified [Tarski]
In the classical concept of truth, 'snow is white' is true if snow is white [Tarski]
Scheme (T) is not a definition of truth [Tarski]
Each interpreted T-sentence is a partial definition of truth; the whole definition is their conjunction [Tarski]
Use 'true' so that all T-sentences can be asserted, and the definition will then be 'adequate' [Tarski]
We don't give conditions for asserting 'snow is white'; just that assertion implies 'snow is white' is true [Tarski]
Tarski gave up on the essence of truth, and asked how truth is used, or how it functions [Tarski, by Horsten]
Tarski did not just aim at a definition; he also offered an adequacy criterion for any truth definition [Tarski, by Halbach]
Tarski enumerates cases of truth, so it can't be applied to new words or languages [Davidson on Tarski]
Tarski define truths by giving the extension of the predicate, rather than the meaning [Davidson on Tarski]
Tarski made truth relative, by only defining truth within some given artificial language [Tarski, by O'Grady]
Tarski has to avoid stating how truths relate to states of affairs [Kirkham on Tarski]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / b. Satisfaction and truth
Truth only applies to closed formulas, but we need satisfaction of open formulas to define it [Burgess on Tarski]
Tarski uses sentential functions; truly assigning the objects to variables is what satisfies them [Tarski, by Rumfitt]
We can define the truth predicate using 'true of' (satisfaction) for variables and some objects [Tarski, by Horsten]
For physicalism, reduce truth to satisfaction, then define satisfaction as physical-plus-logic [Tarski, by Kirkham]
Insight: don't use truth, use a property which can be compositional in complex quantified sentence [Tarski, by Kirkham]
Tarski gave axioms for satisfaction, then derived its explicit definition, which led to defining truth [Tarski, by Davidson]
The best truth definition involves other semantic notions, like satisfaction (relating terms and objects) [Tarski]
Specify satisfaction for simple sentences, then compounds; true sentences are satisfied by all objects [Tarski]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / c. Meta-language for truth
We can't use a semantically closed language, or ditch our logic, so a meta-language is needed [Tarski]
The metalanguage must contain the object language, logic, and defined semantics [Tarski]
3. Truth / F. Semantic Truth / 2. Semantic Truth
Tarski defined truth for particular languages, but didn't define it across languages [Davidson on Tarski]
Tarski didn't capture the notion of an adequate truth definition, as Convention T won't prove non-contradiction [Halbach on Tarski]
Tarski says that his semantic theory of truth is completely neutral about all metaphysics [Tarski, by Haack]
Physicalists should explain reference nonsemantically, rather than getting rid of it [Tarski, by Field,H]
A physicalist account must add primitive reference to Tarski's theory [Field,H on Tarski]
If listing equivalences is a reduction of truth, witchcraft is just a list of witch-victim pairs [Field,H on Tarski]
Tarski made truth respectable, by proving that it could be defined [Tarski, by Halbach]
Tarski had a theory of truth, and a theory of theories of truth [Tarski, by Read]
Tarski's 'truth' is a precise relation between the language and its semantics [Tarski, by Walicki]
Tarskian truth neglects the atomic sentences [Mulligan/Simons/Smith on Tarski]
3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
Tarski's had the first axiomatic theory of truth that was minimally adequate [Tarski, by Horsten]
Tarski defined truth, but an axiomatisation can be extracted from his inductive clauses [Tarski, by Halbach]
Tarski thought axiomatic truth was too contingent, and in danger of inconsistencies [Tarski, by Davidson]
We need an undefined term 'true' in the meta-language, specified by axioms [Tarski]
3. Truth / H. Deflationary Truth / 1. Redundant Truth
Truth can't be eliminated from universal claims, or from particular unspecified claims [Tarski]
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
Semantics is a very modest discipline which solves no real problems [Tarski]
4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
Truth tables give prior conditions for logic, but are outside the system, and not definitions [Tarski]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / d. System T
T adds □p→p for reflexivity, and is ideal for modeling lawhood [Schaffer,J]
5. Theory of Logic / A. Overview of Logic / 3. Value of Logic
Set theory and logic are fairy tales, but still worth studying [Tarski]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
There is no clear boundary between the logical and the non-logical [Tarski]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
A language: primitive terms, then definition rules, then sentences, then axioms, and finally inference rules [Tarski]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Split out the logical vocabulary, make an assignment to the rest. It's logical if premises and conclusion match [Tarski, by Rumfitt]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
Logical consequence is when in any model in which the premises are true, the conclusion is true [Tarski, by Beall/Restall]
Logical consequence: true premises give true conclusions under all interpretations [Tarski, by Hodges,W]
X follows from sentences K iff every model of K also models X [Tarski]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
The truth definition proves semantic contradiction and excluded middle laws (not the logic laws) [Tarski]
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
Identity is invariant under arbitrary permutations, so it seems to be a logical term [Tarski, by McGee]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Logical form can't dictate metaphysics, as it may propose an undesirable property [Schaffer,J]
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
A name denotes an object if the object satisfies a particular sentential function [Tarski]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
Tarski built a compositional semantics for predicate logic, from dependent satisfactions [Tarski, by McGee]
Tarksi invented the first semantics for predicate logic, using this conception of truth [Tarski, by Kirkham]
Semantics is the concepts of connections of language to reality, such as denotation, definition and truth [Tarski]
A language containing its own semantics is inconsistent - but we can use a second language [Tarski]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
A sentence is satisfied when we can assert the sentence when the variables are assigned [Tarski]
Satisfaction is the easiest semantical concept to define, and the others will reduce to it [Tarski]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
The object language/ metalanguage distinction is the basis of model theory [Tarski, by Halbach]
A 'model' is a sequence of objects which satisfies a complete set of sentential functions [Tarski]
5. Theory of Logic / K. Features of Logics / 2. Consistency
Using the definition of truth, we can prove theories consistent within sound logics [Tarski]
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
Tarski avoids the Liar Paradox, because truth cannot be asserted within the object language [Tarski, by Fisher]
The Liar makes us assert a false sentence, so it must be taken seriously [Tarski]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Tarski improved Hilbert's geometry axioms, and without set-theory [Tarski, by Feferman/Feferman]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
If 'there are red roses' implies 'there are roses', then 'there are prime numbers' implies 'there are numbers' [Schaffer,J]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / b. Indispensability of mathematics
If a notion is ontologically basic, it should be needed in our best attempt at science [Schaffer,J]
6. Mathematics / C. Sources of Mathematics / 7. Formalism
Tarski's theory of truth shifted the approach away from syntax, to set theory and semantics [Feferman/Feferman on Tarski]
7. Existence / C. Structure of Existence / 1. Grounding / a. Nature of grounding
Grounding is unanalysable and primitive, and is the basic structuring concept in metaphysics [Schaffer,J]
As causation links across time, grounding links the world across levels [Schaffer,J]
If ground is transitive and irreflexive, it has a strict partial ordering, giving structure [Schaffer,J]
7. Existence / C. Structure of Existence / 2. Reduction
Three types of reduction: Theoretical (of terms), Definitional (of concepts), Ontological (of reality) [Schaffer,J]
7. Existence / C. Structure of Existence / 5. Supervenience / a. Nature of supervenience
Supervenience is just modal correlation [Schaffer,J]
7. Existence / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
The cosmos is the only fundamental entity, from which all else exists by abstraction [Schaffer,J]
7. Existence / D. Theories of Reality / 8. Facts / b. Types of fact
There is only one fact - the True [Schaffer,J]
7. Existence / E. Categories / 4. Category Realism
Maybe categories are just the different ways that things depend on basic substances [Schaffer,J]
8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes
Tropes are the same as events [Schaffer,J]
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
I am a deeply convinced nominalist [Tarski]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
Individuation aims to count entities, by saying when there is one [Schaffer,J]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
No sortal could ever exactly pin down which set of particles count as this 'cup' [Schaffer,J]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
There exist heaps with no integral unity, so we should accept arbitrary composites in the same way [Schaffer,J]
The notion of 'grounding' can explain integrated wholes in a way that mere aggregates can't [Schaffer,J]
9. Objects / F. Identity among Objects / 6. Identity between Objects
Identities can be true despite indeterminate reference, if true under all interpretations [Schaffer,J]
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible
Only ideal conceivability could indicate what is possible [Schaffer,J]
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
Belief in impossible worlds may require dialetheism [Schaffer,J]
11. Knowledge Aims / B. Certain Knowledge / 2. Common Sense Certainty
'Moorean certainties' are more credible than any sceptical argument [Schaffer,J]
13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / a. Agrippa's trilemma
Agrippa's Trilemma: justification is infinite, or ends arbitrarily, or is circular [Agrippa, by Williams,M]
13. Knowledge Criteria / E. Relativism / 1. Relativism
Everything is perceived in relation to another thing (Mode 13) [Agrippa, by Diog. Laertius]
14. Science / D. Explanation / 2. Types of Explanation / b. Contrastive explanations
Explaining 'Adam ate the apple' depends on emphasis, and thus implies a contrast [Schaffer,J]
19. Language / E. Analyticity / 1. Analytic Propositions
Sentences are 'analytical' if every sequence of objects models them [Tarski]
21. Aesthetics / A. Aesthetic Experience / 3. Taste
Taste is the capacity to judge an object or representation which is thought to be beautiful [Tarski, by Schellekens]
26. Natural Theory / A. Speculations on Nature / 1. Nature
I take what is fundamental to be the whole spatiotemporal manifold and its fields [Schaffer,J]
26. Natural Theory / C. Causation / 1. Causation
In causation there are three problems of relata, and three metaphysical problems [Schaffer,J]
Causation may not be transitive; the last event may follow from the first, but not be caused by it [Schaffer,J]
There are at least ten theories about causal connections [Schaffer,J]
Nowadays causation is usually understood in terms of equations and variable ranges [Schaffer,J]
26. Natural Theory / C. Causation / 4. Naturalised causation
Causation transcends nature, because absences can cause things [Schaffer,J]
Causation may not be a process, if a crucial part of the process is 'disconnected' [Schaffer,J]
A causal process needs to be connected to the effect in the right way [Schaffer,J]
Causation can't be a process, because a process needs causation as a primitive [Schaffer,J]
26. Natural Theory / C. Causation / 5. Direction of causation
At least four rivals have challenged the view that causal direction is time direction [Schaffer,J]
Causal order must be temporal, or else causes could be blocked, and time couldn't be explained [Schaffer,J]
Causal order is not temporal, because of time travel, and simultanous, joint or backward causes [Schaffer,J]
26. Natural Theory / C. Causation / 6. Causation as primitive
Causation is primitive; it is too intractable and central to be reduced; all explanations require it [Schaffer,J]
If causation is just observables, or part of common sense, or vacuous, it can't be primitive [Schaffer,J]
26. Natural Theory / C. Causation / 7. Eliminating causation
The notion of causation allows understanding of science, without appearing in equations [Schaffer,J]
Causation is utterly essential for numerous philosophical explanations [Schaffer,J]
26. Natural Theory / C. Causation / 8. Particular Causation / a. Observation of causation
If two different causes are possible in one set of circumstances, causation is primitive [Schaffer,J]
If causation is primitive, it can be experienced in ourselves, or inferred as best explanation [Schaffer,J]
26. Natural Theory / C. Causation / 8. Particular Causation / b. Causal relata
Events are fairly course-grained (just saying 'hello'), unlike facts (like saying 'hello' loudly) [Schaffer,J]
Causal relata are events - or facts, features, tropes, states, situations or aspects [Schaffer,J]
One may defend three or four causal relata, as in 'c causes e rather than e*' [Schaffer,J]
If causal relata must be in nature and fine-grained, neither facts nor events will do [Schaffer,J]
The relata of causation (such as events) need properties as explanation, which need causation! [Schaffer,J]
26. Natural Theory / C. Causation / 8. Particular Causation / d. Selecting the cause
Our selection of 'the' cause is very predictable, so must have a basis [Schaffer,J]
Selecting 'the' cause must have a basis; there is no causation without such a selection [Schaffer,J]
26. Natural Theory / C. Causation / 8. Particular Causation / e. Probabilistic causation
The actual cause may make an event less likely than a possible more effective cause [Schaffer,J]
All four probability versions of causation may need causation to be primitive [Schaffer,J]