Combining Philosophers

All the ideas for Alfred Tarski, Thomas Hobbes and Anaxarchus

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181 ideas

1. Philosophy / C. History of Philosophy / 4. Later European Philosophy / b. Seventeenth century philosophy
Hobbes created English-language philosophy [Hobbes, by Tuck]
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / e. Philosophy as reason
Definitions are the first step in philosophy [Hobbes]
1. Philosophy / D. Nature of Philosophy / 8. Humour
Laughter is a sudden glory in realising the infirmity of others, or our own formerly [Hobbes]
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 / 2. Analysis by Division
Resolve a complex into simple elements, then reconstruct the complex by using them [Hobbes, by MacIntyre]
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 / 2. Aims of Definition
Definitions of things that are caused must express their manner of generation [Hobbes]
2. Reason / D. Definition / 5. Genus and Differentia
Definition is resolution of names into successive genera, and finally the difference [Hobbes]
2. Reason / D. Definition / 8. Impredicative Definition
A defined name should not appear in the definition [Hobbes]
2. Reason / F. Fallacies / 3. Question Begging
'Petitio principii' is reusing the idea to be defined, in disguised words [Hobbes]
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 / G. Formal Mereology / 3. Axioms of Mereology
A part of a part is a part of a whole [Hobbes]
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 / 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]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
If we just say one, one, one, one, we don't know where we have got to [Hobbes]
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 / A. Nature of Existence / 3. Being / a. Nature of Being
Only supernatural means could annihilate anything once it had being [Hobbes]
7. Existence / B. Change in Existence / 1. Nature of Change
Change is nothing but movement [Hobbes]
7. Existence / D. Theories of Reality / 6. Physicalism
Every part of the universe is body, and non-body is not part of it [Hobbes]
8. Modes of Existence / B. Properties / 8. Properties as Modes
Accidents are just modes of thinking about bodies [Hobbes]
8. Modes of Existence / B. Properties / 12. Denial of Properties
Accidents are not parts of bodies (like blood in a cloth); they have accidents as things have a size [Hobbes]
8. Modes of Existence / C. Powers and Dispositions / 3. Powers as Derived
The complete power of an event is just the aggregate of the qualities that produced it [Hobbes]
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
I am a deeply convinced nominalist [Tarski]
8. Modes of Existence / E. Nominalism / 1. Nominalism / b. Nominalism about universals
The only generalities or universals are names or signs [Hobbes]
9. Objects / A. Existence of Objects / 5. Individuation / c. Individuation by location
Bodies are independent of thought, and coincide with part of space [Hobbes]
If you separate the two places of one thing, you will also separate the thing [Hobbes]
If you separated two things in the same place, you would also separate the places [Hobbes]
9. Objects / B. Unity of Objects / 1. Unifying an Object / b. Unifying aggregates
If a whole body is moved, its parts must move with it [Hobbes]
9. Objects / C. Structure of Objects / 2. Hylomorphism / a. Hylomorphism
A chair is wood, and its shape is the form; it isn't 'compounded' of the matter and form [Hobbes]
9. Objects / C. Structure of Objects / 8. Parts of Objects / b. Sums of parts
A body is always the same, whether the parts are together or dispersed [Hobbes]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
To make a whole, parts needn't be put together, but can be united in the mind [Hobbes]
9. Objects / D. Essence of Objects / 5. Essence as Kind
Particulars contain universal things [Hobbes]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / b. Essence not necessities
Some accidental features are permanent, unless the object perishes [Hobbes]
9. Objects / D. Essence of Objects / 13. Nominal Essence
The feature which picks out or names a thing is usually called its 'essence' [Hobbes]
9. Objects / D. Essence of Objects / 15. Against Essentialism
Essence is just an artificial word from logic, giving a way of thinking about substances [Hobbes]
9. Objects / E. Objects over Time / 8. Continuity of Rivers
It is the same river if it has the same source, no matter what flows in it [Hobbes]
9. Objects / E. Objects over Time / 9. Ship of Theseus
Some individuate the ship by unity of matter, and others by unity of form [Hobbes]
If a new ship were made of the discarded planks, would two ships be numerically the same? [Hobbes]
9. Objects / F. Identity among Objects / 3. Relative Identity
As an infant, Socrates was not the same body, but he was the same human being [Hobbes]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
Two bodies differ when (at some time) you can say something of one you can't say of the other [Hobbes]
10. Modality / B. Possibility / 5. Contingency
'Contingent' means that the cause is unperceived, not that there is no cause [Hobbes]
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / b. Conceivable but impossible
We can imagine a point swelling and contracting - but not how this could be done [Hobbes]
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
The qualities of the world are mere appearances; reality is the motions which cause them [Hobbes]
Appearance and reality can be separated by mirrors and echoes [Hobbes]
12. Knowledge Sources / D. Empiricism / 1. Empiricism
Experience can't prove universal truths [Hobbes]
Evidence is conception, which is imagination, which proceeds from the senses [Hobbes]
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius]
13. Knowledge Criteria / D. Scepticism / 5. Dream Scepticism
Dreams must be false because they seem absurd, but dreams don't see waking as absurd [Hobbes]
14. Science / D. Explanation / 2. Types of Explanation / g. Causal explanations
Science aims to show causes and generation of things [Hobbes]
15. Nature of Minds / C. Capacities of Minds / 2. Imagination
Imagination is just weakened sensation [Hobbes]
15. Nature of Minds / C. Capacities of Minds / 10. Conatus/Striving
A 'conatus' is an initial motion, experienced by us as desire or aversion [Hobbes, by Arthur,R]
16. Persons / F. Free Will / 5. Against Free Will
Those actions that follow immediately the last appetite are voluntary [Hobbes]
Freedom is absence of opposition to action; the idea of 'free will' is absurd [Hobbes]
A man cannot will to will, or will to will to will, so the idea of a voluntary will is absurd [Hobbes]
If a man suddenly develops an intention of doing something, the cause is out of his control, not in his will [Hobbes]
16. Persons / F. Free Will / 7. Compatibilism
Liberty and necessity are consistent, as when water freely flows, by necessity [Hobbes]
17. Mind and Body / E. Mind as Physical / 1. Physical Mind
Conceptions and apparitions are just motion in some internal substance of the head [Hobbes]
Sensation is merely internal motion of the sentient being [Hobbes]
18. Thought / A. Modes of Thought / 3. Emotions / e. Basic emotions
Apart from pleasure and pain, the only emotions are appetite and aversion [Hobbes]
The 'simple passions' are appetite, desire, love, aversion, hate, joy, and grief [Hobbes, by Goldie]
18. Thought / B. Mechanics of Thought / 5. Mental Files
Words are not for communication, but as marks for remembering what we have learned [Hobbes]
19. Language / E. Analyticity / 1. Analytic Propositions
Sentences are 'analytical' if every sequence of objects models them [Tarski]
20. Action / C. Motives for Action / 1. Acting on Desires
The will is just the last appetite before action [Hobbes]
It is an error that reason should control the passions, which give right guidance on their own [Hobbes, by Tuck]
20. Action / C. Motives for Action / 3. Acting on Reason / a. Practical reason
Reason is usually general, but deliberation is of particulars [Hobbes]
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 / d. Ethical theory
Good and evil are what please us; goodness and badness the powers causing them [Hobbes]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / h. Expressivism
'Good' is just what we desire, and 'Evil' what we hate [Hobbes]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / j. Ethics by convention
Self-preservation is basic, and people judge differently about that, implying ethical relativism [Hobbes, by Tuck]
Men's natural desires are no sin, and neither are their actions, until law makes it so [Hobbes]
22. Metaethics / B. Value / 1. Nature of Value / f. Ultimate value
There is no absolute good, for even the goodness of God is goodness to us [Hobbes]
22. Metaethics / B. Value / 2. Values / g. Love
Desire and love are the same, but in the desire the object is absent, and in love it is present [Hobbes]
22. Metaethics / B. Value / 2. Values / i. Self-interest
All voluntary acts aim at some good for the doer [Hobbes]
22. Metaethics / C. The Good / 1. Goodness / c. Right and good
Hobbes shifted from talk of 'the good' to talk of 'rights' [Hobbes, by Tuck]
22. Metaethics / C. The Good / 2. Happiness / c. Value of happiness
Life has no end (not even happiness), because we have desires, which presuppose a further end [Hobbes]
23. Ethics / B. Contract Ethics / 1. Contractarianism
Hobbes wants a contract to found morality, but shared values are needed to make a contract [MacIntyre on Hobbes]
A contract is a mutual transfer of rights [Hobbes]
The person who performs first in a contract is said to 'merit' the return, and is owed it [Hobbes]
23. Ethics / B. Contract Ethics / 2. Golden Rule
For Hobbes the Golden Rule concerns not doing things, whereas Jesus encourages active love [Hobbes, by Flanagan]
23. Ethics / B. Contract Ethics / 3. Promise Keeping
In the violent state of nature, the merest suspicion is enough to justify breaking a contract [Hobbes]
23. Ethics / B. Contract Ethics / 4. Value of Authority
Fear of sanctions is the only motive for acceptance of authority that Hobbes can think of [MacIntyre on Hobbes]
Suspicion will not destroy a contract, if there is a common power to enforce it [Hobbes]
23. Ethics / B. Contract Ethics / 5. Free Rider
No one who admitted to not keeping contracts could ever be accepted as a citizen [Hobbes]
If there is a good reason for breaking a contract, the same reason should have stopped the making of it [Hobbes]
23. Ethics / B. Contract Ethics / 7. Prisoner's Dilemma
The first performer in a contract is handing himself over to an enemy [Hobbes]
23. Ethics / B. Contract Ethics / 8. Contract Strategies
Someone who keeps all his contracts when others are breaking them is making himself a prey to others [Hobbes]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / c. Motivation for virtue
Virtues are a means to peaceful, sociable and comfortable living [Hobbes]
23. Ethics / C. Virtue Theory / 3. Virtues / c. Justice
Injustice is the failure to keep a contract, and justice is the constant will to give what is owed [Hobbes]
24. Political Theory / A. Basis of a State / 1. A People / b. The natural life
In time of war the life of man is solitary, poor, nasty, brutish and short [Hobbes]
Hobbes attributed to savages the passions which arise in a law-bound society [Hobbes, by Rousseau]
24. Political Theory / B. Nature of a State / 2. State Legitimacy / a. Sovereignty
Hobbes says the people voluntarily give up their sovereignty, in a contract with a ruler [Hobbes, by Oksala]
25. Social Practice / B. Equalities / 1. Grounds of equality
There is not enough difference between people for one to claim more benefit than another [Hobbes]
Hobbes says people are roughly equal; Locke says there is no right to impose inequality [Hobbes, by Wolff,J]
25. Social Practice / C. Rights / 3. Alienating rights
If we seek peace and defend ourselves, we must compromise on our rights [Hobbes]
25. Social Practice / D. Justice / 2. The Law / c. Natural law
We should obey the laws of nature, provided other people are also obeying them [Hobbes, by Wolff,J]
25. Social Practice / D. Justice / 2. The Law / d. Legal positivism
The legal positivism of Hobbes said law is just formal or procedural [Hobbes, by Jolley]
25. Social Practice / D. Justice / 3. Punishment / a. Right to punish
Punishment should only be for reform or deterrence [Hobbes]
25. Social Practice / E. Policies / 1. War / c. Combatants
I act justly if I follow my Prince in an apparently unjust war, and refusing to fight would be injustice [Hobbes]
25. Social Practice / E. Policies / 2. Religion in Society
If fear of unknown powers is legal it is religion, if it is illegal it is superstition [Hobbes]
25. Social Practice / F. Life Issues / 5. Sexual Morality
Lust involves pleasure, and also the sense of power in pleasing others [Hobbes]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / b. Prime matter
Prime matter is body considered with mere size and extension, and potential [Hobbes]
26. Natural Theory / C. Causation / 1. Causation
Acting on a body is either creating or destroying a property in it [Hobbes]
26. Natural Theory / C. Causation / 8. Particular Causation / c. Conditions of causation
An effect needs a sufficient and necessary cause [Hobbes]
26. Natural Theory / C. Causation / 9. General Causation / a. Constant conjunction
Causation is only observation of similar events following each other, with nothing visible in between [Hobbes]
26. Natural Theory / C. Causation / 9. General Causation / d. Causal necessity
A cause is the complete sum of the features which necessitate the effect [Hobbes]
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
Motion is losing one place and acquiring another [Hobbes]
27. Natural Reality / A. Classical Physics / 1. Mechanics / c. Forces
'Force' is the quantity of movement imposed on something [Hobbes]
27. Natural Reality / D. Time / 2. Passage of Time / k. Temporal truths
Past times can't exist anywhere, apart from in our memories [Hobbes]
28. God / C. Attitudes to God / 4. God Reflects Humanity
The attributes of God just show our inability to conceive his nature [Hobbes]
29. Religion / D. Religious Issues / 1. Religious Commitment / a. Religious Belief
Religion is built on ignorance and misinterpretation of what is unknown or frightening [Hobbes]
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
Belief in an afterlife is based on poorly founded gossip [Hobbes]