A trade-off between material and formal truth: in infor formal al validity (material truth of molecular sentences, i.e. logical relations) A discussion about the extr tra-valid lidity of axioms, outside logical systems How can the axioms of a logical system be justified themselves? Examples: the truth-clause Kp p: Every sentence p that is kn known is thereby tr true If p is known, therefore p is true (in every T-model) Formal truths: logical relations true in every mod odel In every K-model, the truth of Kp entails the truth of p A relative sense of truth: truth-in-a-model (set of true sentences) Does it make sense to talk about extra-validity (cf. matter vs form)? Axioms and obviousness (axiom of parallels, LEM, truth-clause, etc.) Axioms are assumed to be obviously true, naturally accepted
A trade-off between material and formal truth: in infor formal al validity (material truth of molecular sentences, i.e. logical relations) A discussion about the extr tra-valid lidity of axioms, outside logical systems How can the axioms of a logical system be justified themselves? Examples: the truth-clause Kp p: Every sentence p that is kn known is thereby tr true If p is known, therefore p is true (in every T-model) Formal truths: logical relations true in every mod odel In every K-model, the truth of Kp entails the truth of p A relative sense of truth: truth-in-a-model (set of true sentences) Does it make sense to talk about extra-validity (cf. matter vs form)? Axioms and obviousness (axiom of parallels, LEM, truth-clause, etc.) Axioms are assumed to be obviously true, naturally accepted
A trade-off between material and formal truth: in infor formal al validity (material truth of molecular sentences, i.e. logical relations) A discussion about the extr tra-valid lidity of axioms, outside logical systems How can the axioms of a logical system be justified themselves? Examples: the truth-clause Kp p: Every sentence p that is kn known is thereby tr true If p is known, therefore p is true (in every T-model) Formal truths: logical relations true in every mod odel In every K-model, the truth of Kp entails the truth of p A relative sense of truth: truth-in-a-model (set of true sentences) Does it make sense to talk about extr tra-validity (cf. matter vs form)? Axioms and obviousness (axiom of parallels, LEM, truth-clause, etc.) Axioms are assumed to be obviously true, naturally accepted
What if given axioms happen to be false? The whole argument is made irrelevant … … but neither mat ateriall lly, not for formall lly false Extra-validity has to do not with truth, but relevance Can an axiom be said to be “ relevant ” and “ false ” at once? Relevant for what? For whom? False of what? For whom? Is “ relevance ” another name for prag agmatic tic tr truth th? Back to the truth-clause Kp p p : “I have a hand” The skeptic accepts this axiom, but denies the premise Kp Is such an axiom relevant for a skeptic, especially a Pyrrhonian?
What if given axioms happen to be false? The whole argument is made irrelevant … … but neither mat ateriall lly, not for formall lly false Extra-validity has to do not with truth, but relevance Can an axiom be said to be “relevant” and “false” at once? Relevant for what? For whom? False of what? For whom? Is “relevance” another name for prag agmatic tic tr truth th? Back to the truth-clause Kp p p: “I have a hand” The skeptic accepts this axiom, but denies the premise Kp Is such an axiom relevant for a skeptic, especially a Pyrrhonian?
What if given axioms happen to be false? The whole argument is made irrelevant … … but neither mat ateriall lly, not for formall lly false Extra-validity has to do not with truth, but relevance Can an axiom be said to be “relevant” and “false” at once? Relevant for what? For whom? False of what? For whom? Is “relevance” another name for prag agmatic tic tr truth th? Back to the truth-clause Kp p p: “I have a hand” The skeptic accepts this axiom, but denies the premise Kp Is such an axiom relevant for a skeptic, especially a Pyrrhonian?
Pragmatism, as understood here, means a way of doing philosophy that takes seriously the practical human life as a starting point for all philosophic contemplation. (Martela 2010: 2)
Entailment thesis K , ├ K ( and are metavariables) : “I have a hand”, : “I am not a brain in a vat” A case of deaf dialogue: logical agreement, material disagreement G. E. Moore, Pyrrho: both accept the entailment thesis G. E. Moore: accepts K , accepts , accepts K Pyrrho: denies K , accepts , denies K accepts K , accepts , accepts K G. E. Moore: reasons by Modus Ponens Pyrrho: reasons by Modus Tollens Dialogue needs a minimal ag agreement about the premises to be relevant (cf. Socratic dialogues: from for formal to mater terial al agreement, through consistency of the whole)
Entailment thesis K , ├ K ( and are metavariables) : “I have a hand”, : “I am not a brain in a vat” A case of deaf dialogue: logical agreement, material disagreement G. E. Moore, Pyrrho: both accept the entailment thesis G. E. Moore: accepts K , accepts , accepts K Pyrrho: denies K , accepts , denies K (= accepts K , accepts , accepts K ?) G. E. Moore: reasons by Modus Ponens Pyrrho: reasons by Modus Tollens Dialogue needs a minimal ag agreement about the premises to be relevant (cf. Socratic dialogues: from for formal to mater terial al agreement, through consistency of the whole)
Entailment thesis K , ├ K ( and are metavariables) : “I have a hand”, : “I am not a brain in a vat” A case of deaf dialogue: logical agreement, material disagreement G. E. Moore, Pyrrho: both accept the entailment thesis G. E. Moore: accepts K , accepts , accepts K Pyrrho: denies K , accepts , denies K (= accepts K , accepts , accepts K ?) G. E. Moore: reasons by Modus Ponens Pyrrho: reasons by Modus Tollens Dialogue needs a minimal ag agreement about the premises to be relevant (cf. Socratic dialogues: from for formal to mater terial al agreement, through consistency of the whole)
Log ogic ical al truth needs mater terial ial truth to be relevant (cf. truth-preservation) How to obtain material agreement? Any relevant logical truth needs a reflection about truth simpliciter How to warrant the truth of a sentence (material truth)? Is truth ab absolu lute or relati tive ve? A number of competing th theorie ies of f tr truth th: Correspondence (truth is related to corresponding facts) Coherence (truth is consistency between sentences/beliefs) Pragmatic (truth is an epistemic agreement between agents) Only 3 theories? No overlapping about the nature of truth? 2 opposite: ob obje jective ve-subje jecti tive, on onti tic-epis iste temic ic views of truth
Log ogic ical al truth needs mater terial ial truth to be relevant (cf. truth-preservation) How to obtain material agreement? Any relevant logical truth needs a reflection about truth simpliciter How to warrant the truth of a sentence (material truth)? Is truth ab absolu lute or relati tive ve? A number of competing th theorie ies of f tr truth th: Correspondence (truth is related to corresponding facts) Coherence (truth is consistency between sentences/beliefs) Pragmatic (truth is an epistemic agreement between agents) Only 3 theories? No overlapping about the nature of truth? 2 opposite: ob obje jective ve-subje jecti tive, on onti tic-epis iste temic ic views of truth
Log ogic ical al truth needs mater terial ial truth to be relevant (cf. truth-preservation) How to obtain material agreement? Any relevant logical truth needs a reflection about truth simpliciter How to warrant the truth of a sentence (material truth)? Is truth ab absolu lute or relati tive ve? A number of competing th theorie ies of f tr truth th: Correspondence (truth is related to corresponding facts) Coherence (truth is consistency between sentences/beliefs) Pragmatic (truth is an epistemic agreement between agents) Only 3 theories? No overlapping about the nature of truth? 2 opposite: ob obje jective ve-subje jecti tive, on onti tic-epis iste temic ic views of truth
Log ogic ical al truth needs mater terial ial truth to be relevant (cf. truth-preservation) How to obtain material agreement? Any relevant logical truth needs a reflection about truth simpliciter How to warrant the truth of a sentence (material truth)? Is truth ab absolu lute or relati tive ve? A number of competing th theorie ies of f tr truth th: Correspondence (truth is related to corresponding facts) Coherence (truth is consistency between sentences/beliefs) Pragmatic (truth is an epistemic agreement between agents) Only 3 theories? No overlap about the nature of truth? 2 opposite: ob obje jective ve-subje jecti tive, on onti tic-epis iste temic ic views of truth
Niiniluoto (2013): “Is truth absolute or relative?” A list of overlapping theories from the aforementioned pairs - Fallibilism (strong, weak) - Pragmatism - Critical realism - Probabilism - Verisimilitude - Cultural relativism - Perspectivism - Provability
Niiniluoto (2013): “Is truth absolute or relative?” A list of overlapping theories from the aforementioned pairs: - Fallibilism (strong, weak) - Pragmatism - Critical realism - Probabilism - Verisimilitude - Cultural relativism - Perspectivism - Provability
Subjective truth: Subjective relativism (Protagoras : “M an is the measurement of everything ” ) Bp p Plato against Protagoras’ relativism: reduction ad absurdum ( log logical al vs mate terial al truth) The agent a believes p : “This wine is sweet” , therefore p is true for a B a p p The agent b disbelieves p, therefore p is false for b B b p p
Subjective truth: Subjective relativism (Protagoras : “Man is the measurement of everything”) Bp p Plato against Protagoras ’ relativism: reduction ad absurdum ( log logical al vs mate terial al truth) The agent a believes p: “This wine is sweet”, therefore p is true for a B a p p The agent b disbelieves p, therefore p is false for b B b p p
on: , ├ Plato ’s reasoning by con ontrap apos ositi tion 1. If both a and b are right, then it is right to state both p and p ├ (B a p B b p) (p p) 2. Now every contradiction is logically false, i.e. its negation is true ├ (p p) 3. Therefore a and b cannot be right together, i.e. one of them is wrong ├ (B a p B b p) Niiniluoto (2013): according to Twardoswki, Protagorean personal truth predicate would violate classical principles of logic
on: , ├ Plato ’s reasoning by con ontrap apos ositi tion 1. If both a and b are right, then it is right to state both p and p ├ (B a p B b p) (p p) 2. Now every contradiction is logically false, i.e. its negation is true ├ (p p) 3. Therefore a and b cannot be right together, i.e. one of them is wrong ├ (B a p B b p) Niiniluoto (2013): according to Twardoswki, Protagorean personal truth predicate would violate classical principles of logic
on: , ├ Plato ’s reasoning by con ontrap apos ositi tion 1. If both a and b are right, then it is right to state both p and p ├ (B a p B b p) (p p) 2. Now every contradiction is logically false, i.e. its negation is true ├ (p p) 3. Therefore a and b cannot be right together, i.e. one of them is wrong ├ (B a p B b p) Niiniluoto (2013): according to Twardoswki, Protagorean personal truth predicate would violate classical principles of logic
on: , ├ Plato ’s reasoning by con ontrap apos ositi tion 1. If both a and b are right, then it is right to state both p and p ├ (B a p B b p) (p p) 2. Now every contradiction is logically false, i.e. its negation is true ├ (p p) 3. Therefore a and b cannot be right together, i.e. one of them is wrong ├ (B a p B b p) Niiniluoto (2013): according to Twardoswki, Protagorean personal truth predicate would violate classical principles of logic
on: , ├ Plato ’s reasoning by con ontrap apos ositi tion 1. If both a and b are right, then it is right to state both p and p ├ (B a p B b p) (p p) 2. Now every contradiction is logically false, i.e. its negation is true ├ (p p) 3. Therefore a and b cannot be right together, i.e. one of them is wrong ├ (B a p B b p) Niiniluoto (2013): according to Twardoswki, Protagorean personal truth predicate would violate classical principles of logic
Plato assumes ob obje jecti tive truth in the first premise: what is true for an agent is made true simpliciter (beyond anyone’s beliefs ) Any agreement between a and b about p requires a ju justi tific ficati tion on of their beliefs Tp (Bp Jp) A reversal of Plato’s classical definition of knowledge: epis istemic ic truth ├ Kp (Bp Tp Jp) ├ Kp Bp ├ Kp Tp We assume Tarski ’s T-scheme: Tp p (in L) ├ Kp Jp Gettier’s Problem: justification may be insufficient to ground truth ├ \ Jp Kp
Plato assumes ob obje jecti tive truth in the first premise: what is true for an agent is made true simpliciter (beyond anyone’s beliefs) Any agreement between a and b about p requires a ju justi tific ficati tion on of their beliefs Tp (Bp Jp) A reversal of Plato’s classical definition of knowledge: epis istemic ic truth ├ Kp (Bp Tp Jp) ├ Kp Bp ├ Kp Tp We assume Tarski’s T -scheme: Tp p (in L) ├ Kp Jp Gettier’s Problem: justification may be insufficient to ground truth ├ \ Jp Kp
Plato assumes ob obje jecti tive truth in the first premise: what is true for an agent is made true simpliciter (beyond anyone’s beliefs) Any agreement between a and b about p requires a ju justi tific ficati tion on of their beliefs Tp (Bp Jp) A reversal of Plato ’s classical definition of knowledge: epis istemic ic truth ├ Kp (Bp Tp Jp) ├ Kp Bp ├ Kp Tp We assume Tarski’s T -scheme: Tp p (in L) ├ Kp Jp Gettier’s Problem: justification may be insufficient to ground truth ├ \ Jp Kp
Plato assumes ob obje jecti tive truth in the first premise: what is true for an agent is made true simpliciter (beyond anyone’s beliefs) Any agreement between a and b about p requires a ju justi tific ficati tion on of their beliefs Tp (Bp Jp) A reversal of Plato’s classical definition of knowledge: epis istemic ic truth ├ Kp (Bp Tp Jp) ├ Kp Bp ├ Kp Tp We assume Tarski’s T -scheme: Tp p (in L) ├ Kp Jp Gettier ’s Problem: justification may be insufficient to ground truth ├ * Jp Kp
Do a and b discuss within the same model, M? If they disagree about p then, by con onsis istency (logical truth): p is true-in-M a p is true-in-M b (or, equivalently: p is false-in-M b ) “Deaf dialogue”: more than one language in the dialogue Log ogic ical al truth is the sole basic criterion for mat aterial truth, thus far Plato’s argument assumes uniqueness/universality of truth How to obtain common agreement about p, accordingly? Intersubjective truth (fallibilism) Which theory of truth gives the best explanation of the relation between knowledge, truth, belief, and justification? (cf. rele levan ance) My answer: epis istemic truth (truth as assertion: T a p , “ p is true-for- a ”)
Do a and b discuss within the same model, M? If they disagree about p then, by con onsis istency (logical truth): p is true-in-M a p is true-in-M b (or, equivalently: p is false-in-M b ) “Deaf dialogue”: more than one language in the dialogue Log ogic ical al truth is the sole basic criterion for mat aterial truth, thus far Plato’s argument assumes uniq ueness/universality of truth How to obtain common agreement about p, accordingly? Intersubjective truth (fallibilism) Which theory of truth gives the best explanation of the relation between knowledge, truth, belief, and justification? (cf. rele levan ance) My answer: epis istemic truth (truth as assertion: T a p, “p is true -for- a ”)
Do a and b discuss within the same model, M? If they disagree about p then, by con onsis istency (logical truth): p is true-in-M a p is true-in-M b (or, equivalently: p is false-in-M b ) “Deaf dialogue”: more than one language in the dialogue Log ogic ical al truth is the sole basic criterion for mat aterial truth, thus far Plato’s argument assumes uniqueness/universality of truth How to obtain common agreement about p, accordingly? Intersubjective truth (fallibilism) Which theory of truth gives the best explanation of the relation between knowledge, truth, belief, and justification? (cf. rele levan ance) My answer: epis istemic truth (truth as assertion: T a p, “p is true -for- a ”)
Niiniluoto (2013): epis iste temic ic definitions of truth are not relevant, for: (1) Relative truth T a p fails to satisfy Von Wright’s truth -logic ├ T a (p q) T a p T a q ├ T a p T a (p q) ├ T a p T a p ├ T a p T a T a p ├ * T a (p q) T a p T a q ├ * T a p T a p ├ * T a T a p T a p
Niiniluoto (2013): epis iste temic ic definitions of truth are not relevant, for: (1) Relative truth T a p fails to satisfy Von Wright ’s truth -logic ├ T a (p q) T a p T a q ├ T a p T a (p q) ├ T a p T a p ├ T a p T a T a p ├* T a (p q) T a p T a q ├* T a p T a p ├* T a T a p T a p
Niiniluoto (2013): epis iste temic ic definitions of truth are not relevant, for: (1) Relative truth T a p fails to satisfy Von Wright ’s truth -logic ├ T a (p q) T a p T a q ├ T a p T a (p q) ├ T a p T a p ├ T a p T a T a p ├* T a (p q) T a p T a q ├* T a p T a p ├* T a T a p T a p
Niiniluoto (2013): epis iste temic ic definitions of truth are not relevant, for: (2) It introduces om omnis iscie ience into the concept of truth: T a p, p q, T a q
Niiniluoto (2013): epis iste temic ic definitions of truth are not relevant, for: (3) There are no external constraints for truth and falsity, accordingly
Niiniluoto (2013): epis iste temic ic definitions of truth are not relevant, for: (4) Tarski ’s T-equivale alence cannot be sustained, because T a p p does not make sense not valid: B a p p and p B a p are not accepted in doxastic logic
Niiniluoto (2013): epis iste temic ic definitions of truth are not relevant, for: (4) Tarski ’s T-equivale alence cannot be sustained, because T a p p does not make sense not valid: B a p p and p B a p are not accepted in doxastic logic
Niiniluoto (2013): epis iste temic ic definitions of truth are not relevant, for: (4) Tarski ’s T-equivale alence cannot be sustained, because T a p p does not make sense not valid: B a p p and p B a p are not accepted in doxastic logic
Niiniluoto (2013): epis iste temic ic definitions of truth are not relevant, for: (5) Either relative truth has absolute truth-conditions: self-refu futin ting Or it doesn’t, and it results in endless iterations: B a p, B a B a p, B a B a B a B a B a p, …
Niiniluoto (2013): epis iste temic ic definitions of truth are not relevant, for: (5) Either relative truth has absolute truth-conditions: self-refuting Or it doesn’t, and it results in endless iterations: B a p, B a B a p, B a B a B a B a B a p, …
Reply to (1) “Relative truth T a p fails to satisfy Von Wright’s truth - logic” - Why should all of von Wright’s axioms be maintained? - Why is relative truth reduced to the doxastic operator B? - Isn’t relative truth a more complex operator like (T a p B a p & J a p)? - What if relative truth behaves like a weak modality, ?
Reply to (1) “Relative truth T a p fails to satisfy Von Wright’s truth - logic” - Why should all of von Wright’s axioms be maintained? - Why is relative truth reduced to the doxastic operator B? - Isn’t relative truth a more complex operator like (T a p B a p & J a p)? - What if relative truth behaves like a weak modality, ?
Reply to (1) “Relative truth T a p fails to satisfy Von Wright’s truth - logic” - Why should all of von Wright’s axioms be maintained? - Why is relative truth reduced to the doxastic operator B? - Isn’t relative truth a more complex operator like (T a p B a p & J a p)? - What if relative truth behaves like a weak modality, ?
Reply to (1) “Relative truth T a p fails to satisfy Von Wright’s truth - logic” - Why should all of von Wright’s axioms be maintained? - Why is relative truth reduced to the doxastic operator B? - Isn’t relative truth a more complex operator like (T a p B a p & J a p)? - What if relative truth behaves like a weak modality, ?
Reply to (1) “Relative truth T a p fails to satisfy Von Wright’s truth - logic” - Why should all of von Wright’s axioms be maintained? - Why is relative truth reduced to the doxastic operator B? - Isn’t relative truth a more complex operator like (T a p B a p & J a p)? - What if relative truth behaves like a weak modality, ?
Reply to (2) “It introduces the case of omniscience into the concept of truth” What is p q, if not T a (p q)? Unless objective truth is restored, omniscience is just Modus Ponens
Reply to (2) “It introduces the case of omniscience into the concept of truth” - What is p q, if not T a (p q)? - Unless objective truth is restored, omniscience is just Mod odus Pon onens
Reply to (2) “It introduces the case of omniscience into the concept of truth” - What is p q, if not T a (p q)? - Unless objective truth is restored, omniscience is just Mod odus Pon onens
Reply to (3): “There are no external constraints for truth and falsity, accordingly” - T a p can be enriched beyond merely personal belief (see (1)) - “ Personal ” needn’t mean “individual” (cf. intersubjective agreement)
Reply to (3): “There are no external constraints for truth and falsity, accordingly” - T a p can be enriched beyond merely personal belief (see (1)) - “Personal” needn’t mean “ single ” (cf. intersubjective agreement)
Reply to (3): “There are no external constraints for truth and falsity, accordingly” - T a p can be enriched beyond merely personal belief (see (1)) - “Personal” needn’t mean “ single ” (cf. in inter tersubje jecti tive ve agreement)
Reply to (4): “ Tarski ’s T- equivalence cannot be sustained” - Obje jective ve truth is restored again through the formula “p” - What if “p” means p -in- L, or “p for a ”?
Reply to (4): “ Tarski ’s T- equivalence cannot be sustained” - Obje jective ve truth is restored again through the formula “p” - What if “p” means p -in- L, or “p for a ”?
Reply to (4): “ Tarski ’s T- equivalence cannot be sustained” - Obje jective ve truth is restored again through the formula “p” - What if “p” means p -in- L, or “p for a ”?
Reply to (5): “Either relative truth has absolute truth -conditions: self-refuting Or it doesn’t, and it results in endless iterations” - Relativity needn’t be univ iversal al, or self-referential - What does iterated (relative) truth mean? Endless iteration relies upon the failure of Axiom 4 (Hintikka (1962)) - An argument against the mod odal al interpretation of truth, at the best What if truth is rendered as as asserti tion on, or tr truth th-clai aim?
Reply to (5): “Either relative truth has absolute truth -conditions: self-refuting Or it doesn’t, and it results in endless iterations” - Relativity needn’t be univ iversal al, or self-referential - What does iterated (relative) truth mean? Endless iteration relies upon the failure of Axiom 4 (Hintikka (1962)) - An argument against the mod odal al interpretation of truth, at the best What if truth is rendered as as asserti tion on, or tr truth th-clai aim?
Reply to (5): “Either relative truth has absolute truth -conditions: self-refuting Or it doesn’t, and it results in endless iterations” - Relativity needn’t be univ iversal al, or self-referential - What does iterated (relative) truth mean? Endless iteration relies upon the failure of Axiom 4 (Hintikka (1962)) - An argument against the mod odal al interpretation of truth, at the best What if truth is rendered as as asserti tion on, or tr truth th-clai aim?
Reply to (5): “Either relative truth has absolute truth -conditions: self-refuting Or it doesn’t, and it results in endless iterations” - Relativity needn’t be univ iversal al, or self-referential - What does iterated (relative) truth mean? Endless iteration relies upon the failure of Axiom 4 (Hintikka (1962)) - An argument against the mod odal al interpretation of truth, at the best What if truth is rendered as as asserti tion on, or tr truth th-clai aim?
(1)-(5) reduce epistemic truth to mere relativism: T a p = B a p assume ob obje jective ve truth in the definition of T a (cf. Plato ) Two biases in the objections to epis iste temic ic truth: - Uniq iqueness of truth is taken to be granted - Truth is presented as a valu alue (can there be more than one?) An alternative solution: defla lati tion onis ism? “ p is true ” : the sentence S is (true-)in-M You can escape your shadow, by turning the light off You can avoid the debate about the nature of truth, by begging it out How to think of the nature of truth, if not as some ag agreement? With what: reality, system, community, …, ?
(1)-(5) reduce epistemic truth to mere relativism: T a p = B a p assume ob obje jective ve truth in the definition of T a (cf. Plato ) Two biases in the objections to epis iste temic ic truth: - Uniq iqueness of truth is taken to be granted - Truth is presented as a valu alue (can there be more than one?) An alternative solution: defla lati tion onis ism? “p is true”: the sentence S is (true -)in-M You can escape your shadow, by turning the light off You can avoid the debate about the nature of truth, by begging it out How to think of the nature of truth, if not as some ag agreement? With what: reality, system, community, …, ?
(1)-(5) reduce epistemic truth to mere relativism: T a p = B a p assume ob obje jective ve truth in the definition of T a (cf. Plato ) Two biases in the objections to epis iste temic ic truth: - Uniq iqueness of truth is taken to be granted - Truth is presented as a valu alue (can there be more than one?) An alternative solution: defla lati tion onis ism? “p is true”: the sentence S is (true -)in-M You can escape your shadow, by turning the light off You can avoid the debate about the nature of truth, by begging it out How to think of the nature of truth, if not as some ag agreement? With what: reality, system, community, …, ?
(1)-(5) reduce epistemic truth to mere relativism: T a p = B a p assume ob obje jective ve truth in the definition of T a (cf. Plato ) Two biases in the objections to epis iste temic ic truth: - Uniq iqueness of truth is taken to be granted - Truth is presented as a valu alue (can there be more than one?) An alternative solution: defla lati tion onis ism? “p is true”: the sentence S is (true -)in-M You can escape your shadow, by turning the light off You can avoid the debate about the nature of truth, by begging it out How to think of the nature of truth, if not as some ag agreement? With what: reality, system, community, …, ?
(1)-(5) reduce epistemic truth to mere relativism: T a p = B a p assume ob obje jective ve truth in the definition of T a (cf. Plato ) Two biases in the objections to epis iste temic ic truth: - Uniq iqueness of truth is taken to be granted - Truth is presented as a valu alue (can there be more than one?) An alternative solution: defla lati tion onis ism? “p is true”: the sentence S is (true -)in-M You can escape your shadow, by turning the light off You can avoid the debate about the nature of truth, by begging it out How to think of the nature of truth, if not as some ag agreement? With what: reality, system, community, …, ?
Russell (1923): truth as correspondence with fac facts ts A proposition is therefore a class of facts , psychological or linguistic, defined as standing into a certain relation (it can be either assertion or denial , according to the cases) to a certain fact . Beliefs/sentences: truth-bearers “Psychological facts”: assertions
Russell (1923): truth as correspondence with fac facts ts A proposition is therefore a class of facts , psychological or linguistic, defined as standing into a certain relation (it can be either assertion or denial , according to the cases) to a certain fact . Fact: truth-maker Beliefs/sentences: truth-bearers “Psychological facts”: assertions, denials “Linguistic facts”: sentences (affirmative, negative) Beliefs/Sentences are individuated by a fact making these true A proposition is the class of such beliefs/sentences How to warrant the occurrence of such facts, in in prac actic tice?
Russell (1923): truth as correspondence with fac facts ts A proposition is therefore a class of facts , psychological or linguistic, defined as standing into a certain relation (it can be either assertion or denial , according to the cases) to a certain fact . Fact: truth-maker Beliefs/sentences: truth-bearers “Psychological facts”: assertions, denials “Linguistic facts”: sentences (affirmative, negative) Beliefs/Sentences are individuated by a fact making these true A proposition is the class of such beliefs/sentences How to warrant the occurrence of such facts, in in prac actic tice?
Russell (1923): truth as correspondence with fac facts ts A proposition is therefore a class of facts , psychological or linguistic, defined as standing into a certain relation (it can be either assertion or denial , according to the cases) to a certain fact . Fact: truth-maker Beliefs/sentences: truth-bearers “Psychological facts”: assertions, denials “Linguistic facts”: sentences (affirmative, negative) Beliefs/Sentences are individuated by a fact making these true A proposition is the class of such beliefs/sentences How to warrant the occurrence of such facts, in in prac actic tice?
Russell (1923): truth as correspondence with fac facts ts A proposition is therefore a class of facts , psychological or linguistic, defined as standing into a certain relation (it can be either assertion or denial , according to the cases) to a certain fact . Fact: truth-maker Beliefs/sentences: truth-bearers “Psychological facts”: assertions, denials “Linguistic facts”: sentences (affirmative, negative) Beliefs/Sentences are individuated by a fact making these true A proposition is the class of such beliefs/sentences How to warrant the occurrence of such facts, in in prac actic tice?
Peirce (1877: 7): truth as ideal convergence of op opin inion ions The question therefore is, how is true belief (or belief in the real) distinguished from false belief (or belief in fiction). Now, as we have seen (…) the ideas of truth and falsehood , in their full development, appertain exclusively to the experiential method of settling opinion . Truth: agreement between speakers in an ideal community any sentence that ou ought t to be believed by every agent the result of an inquiry process related to agreed beliefs What is the rationale (proto-logic) of such an inquiry process? How to come from simple sentences expressing beliefs to true propositions warranting knowledge?
Peirce (1877: 7): truth as ideal convergence of op opin inion ions The question therefore is, how is true belief (or belief in the real) distinguished from false belief (or belief in fiction). Now, as we have seen (…) the ideas of truth and falsehood , in their full development, appertain exclusively to the experiential method of settling opinion . Truth: agreement between speakers in an ideal community any sentence that ou ought t to be believed by every agent the result of an inquiry process related to agreed beliefs What is the rationale (proto-logic) of such an inquiry process? How to come from simple sentences expressing beliefs to true propositions warranting knowledge? Peirce (1877: 7): truth as ideal convergence of op opin inion ions
Peirce (1877: 7): truth as ideal convergence of op opin inion ions The question therefore is, how is true belief (or belief in the real) distinguished from false belief (or belief in fiction). Now, as we have seen (…) the ideas of truth and falsehood , in their full development, appertain exclusively to the experiential method of settling opinion . Truth: agreement between speakers in an ideal community any sentence that ou ought t to be believed by every agent the result of an inquiry process related to agreed beliefs What is the rationale (proto-logic) of such an inquiry process? How to come from simple sentences expressing beliefs to true propositions warranting knowledge?
2. Truth-Values
Frege: truth is the valu value of a proposition (its logical con ontent) The word “true” indicates the aim of logic as does “beautiful” that of aesthetics or “good” that of ethics. (Frege 1956: 289) Cannot truth be relative as a multi-faceted value (cf. cultu ltural al relati tivis vism)? Proposition: the “thought” ( Gedanke ) expressed by a sentence “A sentence proper is a proper name, and its Bedeutung , if it has one, is a truth-value: the True or the False . Truth is an ob obje jecti tive value: only one value for every proposition (true/false), but different propositions (senses) for the same value
Frege: truth is the valu value of a proposition (its logical con ontent) The word “true” indicates the aim of logic as does “beautiful” that of aesthetics or “good” that of ethics. (Frege 1956: 289) Cannot truth be relative as a multi-faceted value (cf. cultu ltural al relati tivis vism)? Proposition: the “thought” ( Gedanke ) expressed by a sentence “A sentence proper is a proper name, and its Bedeutung , if it has one, is a truth-value: the True or the False . Truth is an ob obje jecti tive value: only one value for every proposition (true/false), but different propositions (senses) for the same value
Frege: truth is the valu value of a proposition (its logical con ontent) The word “true” indicates the aim of logic as does “beautiful” that of aesthetics or “good” that of ethics. (Frege 1956: 289) Cannot truth be relative as a multi-faceted value (cf. cultu ltural al relati tivis vism)? Proposition: the “thought” ( Gedanke ) expressed by a sentence A sentence proper is a proper name, and its reference, if it has one, is a truth-value: the True or the False . Truth is an ob obje jecti tive value: only one value for every proposition (true/false), but different propositions (senses) for the same value
Frege: truth is the valu value of a proposition (its logical con ontent) The word “true” indicates the aim of logic as does “beautiful” that of aesthetics or “good” that of ethics. (Frege 1956: 289) Cannot truth be relative as a multi-faceted value (cf. cultu ltural al relati tivis vism)? Proposition: the “thought” ( Gedanke ) expressed by a sentence A sentence proper is a proper name, and its reference, if it has one, is a truth-value: the True or the False . Truth is an ob obje jecti tive value: only one value for every proposition (true/false), but different propositions (senses) for the same value
“ Frege ’s Axiom” (Suszko): a unique referent for declarative sentences We are therefore driven into accepting the truth-value of a sentence as constituting its reference. By the truth value of a sentence I understand the circumstance that it is true or false. There are no further truth- values. For brevity I call the one the True, the other the False. Every declarative sentence concerned with the reference of its words is therefore to be regarded as a proper name, and its reference, if it has one, is either the true or the false. (Frege 1960: 63) One, or two truth-values? The meaning of biv ivale lence “Falsity”: whatever rejected by the speaker in the inquiry process Only one expected ted value, two possible outcomes (success vs failure)
“ Frege ’s Axiom” ( Suszko): a unique referent for declarative sentences We are therefore driven into accepting the truth-value of a sentence as constituting its reference. By the truth value of a sentence I understand the circumstance that it is true or false. There are no further truth- values. For brevity I call the one the True, the other the False. Every declarative sentence concerned with the reference of its words is therefore to be regarded as a proper name, and its reference, if it has one, is either the true or the false. (Frege 1960: 63) One, or two truth-values? The meaning of biv ivale lence “Falsity”: whatever rejected by the speaker in the inquiry process Only one expected ted value, two possible outcomes (success vs failure)
2 pre conditions for sentences to express a “thought” ( Frege 1960: 127) - A common object of investigation: The being of a thought may also be taken to lie in the possibility of different thinkers’ grasping the thought as one and the same thought. - An object prior to any investigation: But even the act of grasping a thought is not a production of the thought, is not an act of setting its parts in order; for the thought was already true , and so was already there with its parts in order, before it was grasped. A traveler who crosses a mountain-range does not thereby make the mountain-range; no more does the judging subject make a thought by acknowledging its truth. Thought is prior to judgment; what is prior to thought itself?
2 pre conditions for sentences to express a “thought” ( Frege 1960: 127) - A common object of investigation: The being of a thought may also be taken to lie in the possibility of different thinkers’ grasping the thought as one and the same thought. - An object prior to any investigation: But even the act of grasping a thought is not a production of the thought, is not an act of setting its parts in order; for the thought was already true , and so was already there with its parts in order, before it was grasped. A traveler who crosses a mountain-range does not thereby make the mountain-range; no more does the judging subject make a thought by acknowledging its truth. Thought is prior to judgment; what is prior to thought itself?
2 preconditions for sentences to express a “thought” ( Frege 1960: 127) - A common object of investigation: The being of a thought may also be taken to lie in the possibility of different thinkers’ grasping the thought as one and the same thought. - An object prior to any investigation: But even the act of grasping a thought is not a production of the thought, is not an act of setting its parts in order; for the thought was already true , and so was already there with its parts in order, before it was grasped. A traveler who crosses a mountain-range does not thereby make the mountain-range; no more does the judging subject make a thought by acknowledging its truth. Thought is prior to judgment; what is prior to thought itself?
2 pre conditions for sentences to express a “thought” ( Frege 1960: 127) - A common object of investigation: The being of a thought may also be taken to lie in the possibility of different thinkers’ grasping the thought as one and the same thought. - An object prior to any investigation: But even the act of grasping a thought is not a production of the thought, is not an act of setting its parts in order; for the thought was already true , and so was already there with its parts in order, before it was grasped. A traveler who crosses a mountain-range does not thereby make the mountain-range; no more does the judging subject make a thought by acknowledging its truth. Thought is prior to judgment; what is prior to thought itself?
2 problems: 1. The reference: a “ truth-value ” , not a fact? (cf. Slingshot’s Argument) The theory with which Frege’s name is especially associated is one which is apt to strike one at first rather fantastic, being usually expressed as a theory that sentences are names of truth-values . (Prior 1953: 55) 2. What is a Fregean tr truth-make ker, accordingly? The value is not an ideal ob object, but an ideal ac activi vity ty of agreement It is the striving for truth that drives us always to advance from the sense to the reference. (Frege 1960: 63)
2 problems: 1. The reference: a “truth - value”, not a fact? (cf. Slingshot’s Argument) The theory with which Frege’s name is especially associated is one which is apt to strike one at first rather fantastic, being usually expressed as a theory that sentences are names of truth-values . (Prior 1953: 55) 2. What is a Fregean tr truth-make ker, accordingly? The value is not an ideal ob object, but an ideal ac activi vity ty of agreement It is the striving for truth that drives us always to advance from the sense to the reference. (Frege 1960: 63)
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