Combining Philosophers

All the ideas for Alfred Tarski, Thomas Nagel and Peter van Inwagen

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188 ideas

1. Philosophy / A. Wisdom / 3. Wisdom Deflated
There is more insight in fundamental perplexity about problems than in their supposed solutions [Nagel]
1. Philosophy / D. Nature of Philosophy / 1. Philosophy
If your life is to be meaningful as part of some large thing, the large thing must be meaningful [Nagel]
Philosophy is the childhood of the intellect, and a culture can't skip it [Nagel]
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / b. Philosophy as transcendent
It seems mad, but the aim of philosophy is to climb outside of our own minds [Nagel]
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 / G. Scientific Philosophy / 3. Scientism
Modern philosophy tends to be a theory-constructing extension of science, but there is also problem-solving [Nagel]
2. Reason / A. Nature of Reason / 5. Objectivity
Views are objective if they don't rely on a person's character, social position or species [Nagel]
Things cause perceptions, properties have other effects, hence we reach a 'view from nowhere' [Nagel, by Reiss/Sprenger]
Realism invites scepticism because it claims to be objective [Nagel]
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 / D. Definition / 12. Paraphrase
We could refer to tables as 'xs that are arranged tablewise' [Inwagen]
3. Truth / A. Truth Problems / 2. Defining Truth
In everyday language, truth seems indefinable, inconsistent, and illogical [Tarski]
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]
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
Scheme (T) is not a definition of truth [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]
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]
Use 'true' so that all T-sentences can be asserted, and the definition will then be 'adequate' [Tarski]
Each interpreted T-sentence is a partial definition of truth; the whole definition is their conjunction [Tarski]
We don't give conditions for asserting 'snow is white'; just that assertion implies 'snow is white' is true [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 defined truth, but an axiomatisation can be extracted from his inductive clauses [Tarski, by Halbach]
Tarski's had the first axiomatic theory of truth that was minimally adequate [Tarski, by Horsten]
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 / F. Set Theory ST / 8. Critique of Set Theory
What in the real world could ground the distinction between the sets {A,{A,B}} and {B,{A,B}}? [Inwagen]
4. Formal Logic / G. Formal Mereology / 1. Mereology
Mereology is 'nihilistic' (just atoms) or 'universal' (no restrictions on what is 'whole') [Inwagen, by Varzi]
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]
The 'Law' of Excluded Middle needs all propositions to be definitely true or definitely false [Inwagen]
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 / 4. Variables in Logic
Variables are just like pronouns; syntactic explanations get muddled over dummy letters [Inwagen]
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
A 'model' is a sequence of objects which satisfies a complete set of sentential functions [Tarski]
The object language/ metalanguage distinction is the basis of model theory [Tarski, by Halbach]
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]
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / b. The Heap paradox ('Sorites')
There are no heaps [Inwagen]
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 / 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 / 5. Supervenience / c. Significance of supervenience
Pure supervenience explains nothing, and is a sign of something fundamental we don't know [Nagel]
7. Existence / C. Structure of Existence / 8. Stuff / a. Pure stuff
I reject talk of 'stuff', and treat it in terms of particles [Inwagen]
7. Existence / D. Theories of Reality / 10. Vagueness / d. Vagueness as linguistic
Singular terms can be vague, because they can contain predicates, which can be vague [Inwagen]
8. Modes of Existence / B. Properties / 7. Emergent Properties
Emergent properties appear at high levels of complexity, but aren't explainable by the lower levels [Nagel]
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
I am a deeply convinced nominalist [Tarski]
9. Objects / A. Existence of Objects / 1. Physical Objects
Material objects are in space and time, move, have a surface and mass, and are made of some stuff [Inwagen]
Maybe table-shaped particles exist, but not tables [Inwagen, by Lowe]
9. Objects / A. Existence of Objects / 6. Nihilism about Objects
Nihilism says composition between single things is impossible [Inwagen]
If there are no tables, but tables are things arranged tablewise, the denial of tables is a contradiction [Liggins on Inwagen]
Actions by artefacts and natural bodies are disguised cooperations, so we don't need them [Inwagen]
9. Objects / B. Unity of Objects / 1. Unifying an Object / b. Unifying aggregates
Every physical thing is either a living organism or a simple [Inwagen]
9. Objects / B. Unity of Objects / 3. Unity Problems / c. Statue and clay
The statue and lump seem to share parts, but the statue is not part of the lump [Inwagen]
If you knead clay you make an infinite series of objects, but they are rearrangements, not creations [Inwagen]
9. Objects / C. Structure of Objects / 3. Matter of an Object
I assume matter is particulate, made up of 'simples' [Inwagen]
9. Objects / C. Structure of Objects / 5. Composition of an Object
If contact causes composition, do two colliding balls briefly make one object? [Inwagen]
If bricks compose a house, that is at least one thing, but it might be many things [Inwagen]
9. Objects / C. Structure of Objects / 8. Parts of Objects / a. Parts of objects
I think parthood involves causation, and not just a reasonably stable spatial relationship [Inwagen]
We can deny whole objects but accept parts, by referring to them as plurals within things [Inwagen, by Liggins]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
Special Composition Question: when is a thing part of something? [Inwagen]
9. Objects / D. Essence of Objects / 8. Essence as Explanatory
The essence of a star includes the released binding energy which keeps it from collapse [Inwagen]
9. Objects / D. Essence of Objects / 11. Essence of Artefacts
The persistence of artifacts always covertly involves intelligent beings [Inwagen]
9. Objects / E. Objects over Time / 7. Intermittent Objects
When an electron 'leaps' to another orbit, is the new one the same electron? [Inwagen]
9. Objects / E. Objects over Time / 9. Ship of Theseus
If you reject transitivity of vague identity, there is no Ship of Theseus problem [Inwagen]
9. Objects / F. Identity among Objects / 1. Concept of Identity
We should talk of the transitivity of 'identity', and of 'definite identity' [Inwagen]
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Actuality proves possibility, but that doesn't explain how it is possible [Inwagen]
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
Counterparts reduce counterfactual identity to problems about similarity relations [Inwagen]
10. Modality / E. Possible worlds / 3. Transworld Objects / e. Possible Objects
A merely possible object clearly isn't there, so that is a defective notion [Inwagen]
Merely possible objects must be consistent properties, or haecceities [Inwagen]
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / b. Primary/secondary
Modern science depends on the distinction between primary and secondary qualities [Nagel]
We achieve objectivity by dropping secondary qualities, to focus on structural primary qualities [Nagel]
12. Knowledge Sources / B. Perception / 4. Sense Data / d. Sense-data problems
Sense-data are a false objectification of what is essentially subjective [Nagel]
13. Knowledge Criteria / B. Internal Justification / 2. Pragmatic justification
Epistemology is centrally about what we should believe, not the definition of knowledge [Nagel]
13. Knowledge Criteria / C. External Justification / 5. Controlling Beliefs
We can't control our own beliefs [Nagel]
13. Knowledge Criteria / C. External Justification / 8. Social Justification
Justifications come to an end when we want them to [Nagel]
13. Knowledge Criteria / D. Scepticism / 6. Scepticism Critique
Scepticism is based on ideas which scepticism makes impossible [Nagel]
13. Knowledge Criteria / E. Relativism / 4. Cultural relativism
You would have to be very morally lazy to ignore criticisms of your own culture [Nagel]
14. Science / C. Induction / 4. Reason in Induction
Observed regularities are only predictable if we assume hidden necessity [Nagel]
15. Nature of Minds / A. Nature of Mind / 1. Mind / a. Mind
Inner v outer brings astonishment that we are a particular person [Nagel]
15. Nature of Minds / A. Nature of Mind / 5. Unity of Mind
Brain bisection suggests unity of mind isn't all-or-nothing [Nagel, by Lockwood]
15. Nature of Minds / B. Features of Minds / 1. Consciousness / b. Essence of consciousness
An organism is conscious if and only if there is something it is like to be that organism [Nagel]
16. Persons / B. Nature of the Self / 4. Presupposition of Self
Personal identity cannot be fully known a priori [Nagel]
The question of whether a future experience will be mine presupposes personal identity [Nagel]
We may be unable to abandon personal identity, even when split-brains have undermined it [Nagel]
If you assert that we have an ego, you can still ask if that future ego will be me [Nagel]
16. Persons / D. Continuity of the Self / 4. Split Consciousness
I can't even conceive of my brain being split in two [Nagel]
16. Persons / F. Free Will / 1. Nature of Free Will
The most difficult problem of free will is saying what the problem is [Nagel]
16. Persons / F. Free Will / 7. Compatibilism
Determinism clashes with free will, as the past determines action, and is beyond our control [Inwagen, by Jackson]
17. Mind and Body / A. Mind-Body Dualism / 7. Zombies
Can we describe our experiences to zombies? [Nagel]
17. Mind and Body / D. Property Dualism / 6. Mysterianism
Nagel's title creates an impenetrable mystery, by ignoring a bat's ways that may not be "like" anything [Dennett on Nagel]
We can't be objective about experience [Nagel]
17. Mind and Body / E. Mind as Physical / 7. Anti-Physicalism / d. Explanatory gap
Physicalism should explain how subjective experience is possible, but not 'what it is like' [Kirk,R on Nagel]
19. Language / A. Nature of Meaning / 6. Meaning as Use
The meaning of a word contains all its possible uses as well as its actual ones [Nagel]
19. Language / E. Analyticity / 1. Analytic Propositions
Sentences are 'analytical' if every sequence of objects models them [Tarski]
20. Action / C. Motives for Action / 5. Action Dilemmas / c. Omissions
Noninterference requires justification as much as interference does [Nagel]
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]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / a. Preconditions for ethics
Morality must be motivating, and not because of pre-moral motives [Nagel]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / d. Ethical theory
There is no one theory of how to act (or what to believe) [Nagel]
22. Metaethics / B. Value / 1. Nature of Value / c. Objective value
Total objectivity can't see value, but it sees many people with values [Nagel]
22. Metaethics / B. Value / 2. Values / e. Death
We don't worry about the time before we were born the way we worry about death [Nagel]
22. Metaethics / B. Value / 2. Values / f. Altruism
If our own life lacks meaning, devotion to others won't give it meaning [Nagel]
22. Metaethics / C. The Good / 1. Goodness / f. Good as pleasure
Pain doesn't have a further property of badness; it gives a reason for its avoidance [Nagel]
22. Metaethics / C. The Good / 1. Goodness / i. Moral luck
Moral luck can arise in character, preconditions, actual circumstances, and outcome [Nagel]
23. Ethics / B. Contract Ethics / 6. Game Theory
Game theory misses out the motivation arising from the impersonal standpoint [Nagel]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / d. Virtue theory critique
Virtue theory needs an external standard to judge behaviour and character [Inwagen, by Statman]
23. Ethics / D. Deontological Ethics / 1. Deontology
Something may be 'rational' either because it is required or because it is acceptable [Nagel]
23. Ethics / D. Deontological Ethics / 2. Duty
If cockroaches can't think about their actions, they have no duties [Nagel]
23. Ethics / D. Deontological Ethics / 3. Universalisability
The general form of moral reasoning is putting yourself in other people's shoes [Nagel]
As far as possible we should become instruments to realise what is best from an eternal point of view [Nagel]
If we can decide how to live after stepping outside of ourselves, we have the basis of a moral theory [Nagel]
In ethics we abstract from our identity, but not from our humanity [Nagel]
We should see others' viewpoints, but not lose touch with our own values [Nagel]
23. Ethics / D. Deontological Ethics / 4. Categorical Imperative
I can only universalise a maxim if everyone else could also universalise it [Nagel]
23. Ethics / D. Deontological Ethics / 6. Motivation for Duty
We find new motives by discovering reasons for action different from our preexisting motives [Nagel]
23. Ethics / E. Utilitarianism / 3. Motivation for Altruism
Utilitarianism is too demanding [Nagel]
23. Ethics / F. Existentialism / 2. Nihilism
If a small brief life is absurd, then so is a long and large one [Nagel]
24. Political Theory / A. Basis of a State / 4. Original Position / c. Difference principle
An egalitarian system must give priority to those with the worst prospects in life [Nagel]
24. Political Theory / D. Ideologies / 6. Liberalism / c. Liberal equality
A legitimate system is one accepted as both impartial and reasonably partial [Nagel]
25. Social Practice / B. Equalities / 1. Grounds of equality
The ideal of acceptability to each individual underlies the appeal to equality [Nagel]
Equality was once opposed to aristocracy, but now it opposes public utility and individual rights [Nagel]
In judging disputes, should we use one standard, or those of each individual? [Nagel]
25. Social Practice / B. Equalities / 2. Political equality
Equality nowadays is seen as political, social, legal and economic [Nagel]
Equality can either be defended as good for society, or as good for individual rights [Nagel]
Democracy is opposed to equality, if the poor are not a majority [Nagel]
25. Social Practice / C. Rights / 1. Basis of Rights
A morality of rights is very minimal, leaving a lot of human life without restrictions or duties [Nagel]
26. Natural Theory / C. Causation / 9. General Causation / d. Causal necessity
Given the nature of heat and of water, it is literally impossible for water not to boil at the right heat [Nagel]
27. Natural Reality / B. Modern Physics / 3. Chromodynamics / a. Chromodynamics
The strong force pulls, but also pushes apart if nucleons get too close together [Inwagen]
27. Natural Reality / F. Chemistry / 2. Modern Elements
Is one atom a piece of gold, or is a sizable group of atoms required? [Inwagen]
27. Natural Reality / G. Biology / 2. Life
One's mental and other life is centred on the brain, unlike any other part of the body [Inwagen]
If God were to 'reassemble' my atoms of ten years ago, the result would certainly not be me [Inwagen]
Life is vague at both ends, but could it be totally vague? [Inwagen]
At the lower level, life trails off into mere molecular interaction [Inwagen]
Being part of an organism's life is a matter of degree, and vague [Inwagen]
A flame is like a life, but not nearly so well individuated [Inwagen]
A tumour may spread a sort of life, but it is not a life, or an organism [Inwagen]
Unlike waves, lives are 'jealous'; it is almost impossible for them to overlap [Inwagen]
The chemical reactions in a human life involve about sixteen elements [Inwagen]
Some events are only borderline cases of lives [Inwagen]
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
There is no reason to think that mere existence is a valuable thing [Inwagen]