74 ideas
5896 | Speak the truth, for this alone deifies man [Pythagoras, by Porphyry] |
Full Idea: Pythagoras advised above all things to speak the truth, for this alone deifies man. | |
From: report of Pythagoras (reports [c.530 BCE]) by Porphyry - Life of Pythagoras §41 | |
A reaction: Idea 4421 (of Nietzsche) stands in contrast to this. I am not quite sure why speaking the truth has such a high value. I am inclined to a minimalist view, which is just that philosophy is an attempt to speak the truth, as fishermen try to catch fish. |
3051 | Pythagoras discovered the numerical relation of sounds on a string [Pythagoras, by Diog. Laertius] |
Full Idea: Pythagoras discovered the numerical relation of sounds on a string. | |
From: report of Pythagoras (reports [c.530 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 08.1.11 |
16325 | Analysis rests on natural language, but its ideal is a framework which revises language [Halbach] |
Full Idea: For me, although the enterprise of philosophical analysis is driven by natural language, its goal is not a linguistic analysis of English but rather an expressively strong framework that may at best be seen as a revision of English. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 12) | |
A reaction: I agree, but the problem is that there are different ideals for the revision, which may be in conflict. Logicians, mathematicians, metaphysicians, scientists, moralists and aestheticians are queueing up to improve in their own way. |
16292 | An explicit definition enables the elimination of what is defined [Halbach] |
Full Idea: Explicit definitions allow for a complete elimination of the defined notion (at least in extensional contexts). | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 1) | |
A reaction: If the context isn't extensional (concerning the things themselves) then we could define one description of it, but be unable to eliminate it under another description. Elimination is no the aim of an Aristotelian definition. Halbach refers to truth. |
16307 | Don't trust analogies; they are no more than a guideline [Halbach] |
Full Idea: Arguments from analogy are to be distrusted: at best they can serve as heuristics. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 4) |
16339 | Truth axioms prove objects exist, so truth doesn't seem to be a logical notion [Halbach] |
Full Idea: Two typed disquotation sentences, truth axioms of TB, suffice for proving that there at least two objects. Hence truth is not a logical notion if one expects logical notions to be ontologically neutral. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 21.2) |
16330 | Truth-value 'gluts' allow two truth values together; 'gaps' give a partial conception of truth [Halbach] |
Full Idea: Truth-value 'gluts' correspond to a so-called dialethic conception of truth; excluding gluts and admitting only 'gaps' leads to a conception of what is usually called 'partial' truth. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 15.2) | |
A reaction: Talk of 'gaps' and 'gluts' seem to be the neatest way of categorising views of truth. I want a theory with no gaps or gluts. |
16324 | Any definition of truth requires a metalanguage [Halbach] |
Full Idea: It is plain that the distinction between object and metalanguage is required for the definability of truth. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 11) | |
A reaction: Halbach's axiomatic approach has given up on definability, and therefore it can seek to abandon the metalanguage and examine 'type-free' theories. |
16293 | Traditional definitions of truth often make it more obscure, rather than less [Halbach] |
Full Idea: A common complaint against traditional definitional theories of truth is that it is far from clear that the definiens is not more in need of clarification than the definiendum (that is, the notion of truth). | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 1) | |
A reaction: He refers to concepts like 'correspondence', 'facts', 'coherence' or 'utility', which are said to be trickier to understand than 'true'. I suspect that philosophers like Halbach confuse 'clear' with 'precise'. Coherence is quite clear, but imprecise. |
16301 | If people have big doubts about truth, a definition might give it more credibility [Halbach] |
Full Idea: If one were wondering whether truth should be considered a legitimate notion at all, a definition might be useful in dispersing doubts about its legitimacy. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 3) | |
A reaction: Halbach is proposing to skip definitions, and try to give rules for using 'true' instead, but he doesn't rule out definitions. A definition of 'knowledge' or 'virtue' or 'democracy' might equally give those credibility. |
15063 | Some sentences depend for their truth on worldly circumstances, and others do not [Fine,K] |
Full Idea: There is a distinction between worldly and unworldly sentences, between sentences that depend for their truth upon the worldly circumstances and those that do not. | |
From: Kit Fine (Necessity and Non-Existence [2005], Intro) | |
A reaction: Fine is fishing around in the area between the necessary, the a priori, truthmakers, and truth-conditions. He appears to be attempting a singlehanded reconstruction of the concepts of metaphysics. Is he major, or very marginal? |
16297 | Semantic theories avoid Tarski's Theorem by sticking to a sublanguage [Halbach] |
Full Idea: In semantic theories (e.g.Tarski's or Kripke's), a definition evades Tarski's Theorem by restricting the possible instances in the schema T[φ]↔φ to sentences of a proper sublanguage of the language formulating the equivalences. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 1) | |
A reaction: The schema says if it's true it's affirmable, and if it's affirmable it's true. The Liar Paradox is a key reason for imposing this restriction. |
16337 | Disquotational truth theories are short of deductive power [Halbach] |
Full Idea: The problem of restricted deductive power has haunted disquotational theories of truth (…because they can't prove generalisations). | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 19.5) |
16326 | The main semantic theories of truth are Kripke's theory, and revisions semantics [Halbach] |
Full Idea: Revision semantics is arguably the main competitor of Kripke's theory of truth among semantic truth theories. …In the former one may hope through revision to arrive at better and better models, ..sorting out unsuitable extensions of the truth predicate. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 14) | |
A reaction: Halbach notes later that Kripke's theory (believe it or not) is considerably simpler than revision semantics. |
16299 | Gödel numbering means a theory of truth can use Peano Arithmetic as its base theory [Halbach] |
Full Idea: Often syntactic objects are identified with their numerical codes. …Expressions of a countable formal language can be coded in the natural numbers. This allows a theory of truth to use Peano Arithmetic (with its results) as a base theory. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 2) | |
A reaction: The numbering system is the famous device invented by Gödel for his great proof of incompleteness. This idea is a key to understanding modern analytic philosophy. It is the bridge which means philosophical theories can be treated mathematically. |
16340 | Truth axioms need a base theory, because that is where truth issues arise [Halbach] |
Full Idea: Considering the truth axioms in the absence of a base theory is not very sensible because characteristically truth theoretic reasoning arises from the interplay of the truth axioms with the base theory. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 21.2) | |
A reaction: The base theory usually seems to be either Peano arithmetic or set theory. We might say that introverted thought (e.g. in infants) has little use for truth; it is when you think about the world that truth becomes a worry. |
16305 | We know a complete axiomatisation of truth is not feasible [Halbach] |
Full Idea: In the light of incompleteness phenomena, one should not expect a categorical axiomatisation of truth to be feasible, but this should not keep one from studying axiomatic theories of truth (or of arithmetic). | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 3) | |
A reaction: This, of course, is because of Gödel's famous results. It is important to be aware in this field that there cannot be a dream of a final theory, so we are just seeing what can be learned about truth. |
16311 | To axiomatise Tarski's truth definition, we need a binary predicate for his 'satisfaction' [Halbach] |
Full Idea: If the clauses of Tarski's definition of truth are turned into axioms (as Davidson proposed) then a primitive binary predicate symbol for satisfaction is needed, as Tarski defined truth in terms of satisfaction. Standard language has a unary predicate. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 5.2) |
16313 | A theory is 'conservative' if it adds no new theorems to its base theory [Halbach, by PG] |
Full Idea: A truth theory is 'conservative' if the addition of the truth predicate does not add any new theorems to the base theory. | |
From: report of Volker Halbach (Axiomatic Theories of Truth [2011], 6 Df 6.6) by PG - Db (ideas) | |
A reaction: Halbach presents the definition more formally, and this is my attempt at getting it into plain English. Halbach uses Peano Arithmetic as his base theory, but set theory is also sometimes used. |
16315 | The Tarski Biconditional theory TB is Peano Arithmetic, plus truth, plus all Tarski bi-conditionals [Halbach] |
Full Idea: The truth theory TB (Tarski Biconditional) is all the axioms of Peano Arithmetic, including all instances of the induction schema with the truth predicate, plus all the sentences of the form T[φ] ↔ φ. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 7) | |
A reaction: The biconditional formula is the famous 'snow is white' iff snow is white. The truth of the named sentence is equivalent to asserting the sentence. This is a typed theory of truth, and it is conservative over PA. |
16318 | Compositional Truth CT has the truth of a sentence depending of the semantic values of its constituents [Halbach] |
Full Idea: In the typed Compositional Truth theory CT, it is compositional because the truth of a sentence depends on the semantic values of the constituents of that sentence. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 8) | |
A reaction: [axioms on p. 65 of Halbach] |
16322 | CT proves PA consistent, which PA can't do on its own, so CT is not conservative over PA [Halbach] |
Full Idea: Compositional Truth CT proves the consistency of Peano arithmetic, which is not provable in Peano arithmetic by Gödel's second incompleteness theorem. Hence the theory CT is not conservative over Peano arithmetic. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 8.6) |
16314 | Theories of truth are 'typed' (truth can't apply to sentences containing 'true'), or 'type-free' [Halbach] |
Full Idea: I sort theories of truth into the large families of 'typed' and 'type-free'. Roughly, typed theories prohibit a truth predicate's application to sentences with occurrences of that predicate, and one cannot prove the truth of sentences containing 'true'. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], II Intro) | |
A reaction: The problem sentence the typed theories are terrified of is the Liar Sentence. Typing produces a hierarchy of languages, referring down to the languages below them. |
16294 | Axiomatic truth doesn't presuppose a truth-definition, though it could admit it at a later stage [Halbach] |
Full Idea: Choosing an axiomatic approach to truth might well be compatible with the view that truth is definable; the definability of truth is just not presupposed at the outset. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 1) | |
A reaction: Is it possible that a successful axiomatisation is a successful definition? |
16327 | Friedman-Sheard is type-free Compositional Truth, with two inference rules for truth [Halbach] |
Full Idea: The Friedman-Sheard truth system FS is based on compositional theory CT. The axioms of FS are obtained by relaxing the type restriction on the CT-axioms, and adding rules inferring sentences from their truth, and vice versa. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 15) | |
A reaction: The rules are called NEC and CONEC by Halbach. The system FSN is FS without the two rules. |
16331 | The KF is much stronger deductively than FS, which relies on classical truth [Halbach] |
Full Idea: The Kripke-Feferman theory is relatively deductively very strong. In particular, it is much stronger than its competitor FS, which is based on a completely classical notion of truth. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 15.3) |
16329 | Kripke-Feferman theory KF axiomatises Kripke fixed-points, with Strong Kleene logic with gluts [Halbach] |
Full Idea: The Kripke-Feferman theory KF is an axiomatisation of the fixed points of an operator, that is, of a Kripkean fixed-point semantics with the Strong Kleene evaluation schema with truth-value gluts. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 15.1) |
16332 | The KF theory is useful, but it is not a theory containing its own truth predicate [Halbach] |
Full Idea: KF is useful for explicating Peano arithmetic, but it certainly does not come to close to being a theory that contains its own truth predicate. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 16) | |
A reaction: Since it is a type-free theory, its main philosophical aspiration was to contain its own truth predicate, so that is bad news (for philosophers). |
16320 | Some say deflationism is axioms which are conservative over the base theory [Halbach] |
Full Idea: Some authors have tried to understand the deflationist claim that truth is not a substantial notion as the claim that a satisfactory axiomatisation of truth should be conservative over the base theory. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 8) |
16338 | Deflationism says truth is a disquotation device to express generalisations, adding no new knowledge [Halbach] |
Full Idea: There are two doctrines at the core of deflationism. The first says truth is a device of disquotation used to express generalisations, and the second says truth is a thin notion that contributes nothing to our knowledge of the world | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 21) |
16316 | Deflationists say truth is just for expressing infinite conjunctions or generalisations [Halbach] |
Full Idea: Deflationists do not hold that truth is completely dispensable. They claim that truth serves the purpose of expressing infinite conjunctions or generalisations. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 7) | |
A reaction: It is also of obvious value as a shorthand in ordinary conversation, but rigorous accounts can paraphrase that out. 'What he said is true'. 'Pick out the true sentences from p,q,r and s' seems to mean 'affirm some of them'. What does 'affirm' mean? |
16317 | The main problem for deflationists is they can express generalisations, but not prove them [Halbach] |
Full Idea: The main criticism that deflationist theories based on the disquotation sentences or similar axioms have to meet was raised by Tarski: the disquotation sentences do not allow one to prove generalisations. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 7) |
16319 | Compositional Truth CT proves generalisations, so is preferred in discussions of deflationism [Halbach] |
Full Idea: Compositional Truth CT and its variants has desirable generalisations among its logical consequences, so they seem to have ousted purely disquotational theories such as TB in the discussion on deflationism. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 8) |
16335 | In Strong Kleene logic a disjunction just needs one disjunct to be true [Halbach] |
Full Idea: In Strong Kleene logic a disjunction of two sentences is true if at least one disjunct is true, even when the other disjunct lacks a truth value. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 18) | |
A reaction: This sounds fine to me. 'Either I'm typing this or Homer had blue eyes' comes out true in any sensible system. |
16334 | In Weak Kleene logic there are 'gaps', neither true nor false if one component lacks a truth value [Halbach] |
Full Idea: In Weak Kleene Logic, with truth-value gaps, a sentence is neither true nor false if one of its components lacks a truth value. A line of the truth table shows a gap if there is a gap anywhere in the line, and the other lines are classical. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 18) | |
A reaction: This will presumably apply even if the connective is 'or', so a disjunction won't be true, even if one disjunct is true, when the other disjunct is unknown. 'Either 2+2=4 or Lot's wife was left-handed' sounds true to me. Odd. |
16309 | Every attempt at formal rigour uses some set theory [Halbach] |
Full Idea: Almost any subject with any formal rigour employs some set theory. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 4.1) | |
A reaction: This is partly because mathematics is often seen as founded in set theory, and formal rigour tends to be mathematical in character. |
16333 | The underestimated costs of giving up classical logic are found in mathematical reasoning [Halbach] |
Full Idea: The costs of giving up classical logic are easily underestimated, …the price being paid in terms of mathematical reasoning. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 16.2) | |
A reaction: No one cares much about such costs, until you say they are 'mathematical'. Presumably this is a message to Graham Priest and his pals. |
16310 | A theory is some formulae and all of their consequences [Halbach] |
Full Idea: A theory is a set of formulae closed under first-order logical consequence. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 5.1) |
16341 | Normally we only endorse a theory if we believe it to be sound [Halbach] |
Full Idea: If one endorses a theory, so one might argue, one should also take it to be sound. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 22.1) |
16344 | Soundness must involve truth; the soundness of PA certainly needs it [Halbach] |
Full Idea: Soundness seems to be a notion essentially involving truth. At least I do not know how to fully express the soundness of Peano arithmetic without invoking a truth predicate. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 22.1) | |
A reaction: I suppose you could use some alternative locution such as 'assertible' or 'cuddly'. Intuitionists seem a bit vague about the truth end of things. |
16342 | You cannot just say all of Peano arithmetic is true, as 'true' isn't part of the system [Halbach] |
Full Idea: One cannot just accept that all the theorems of Peano arithmetic are true when one accepts Peano arithmetic as the notion of truth is not available in the language of arithmetic. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 22.1) | |
A reaction: This is given as the reason why Kreisel and Levy (1968) introduced 'reflection principles', which allow you to assert whatever has been proved (with no mention of truth). (I think. The waters are closing over my head). |
16347 | Many new paradoxes may await us when we study interactions between frameworks [Halbach] |
Full Idea: Paradoxes that arise from interaction of predicates such as truth, necessity, knowledge, future and past truths have receive little attention. There may be many unknown paradoxes lurking when we develop frameworks with these intensional notions. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 24.2) | |
A reaction: Nice. This is a wonderful pointer to new research in the analytic tradition, in which formal problems will gradually iron out our metaphysical framework. |
16336 | The liar paradox applies truth to a negated truth (but the conditional will serve equally) [Halbach] |
Full Idea: An essential feature of the liar paradox is the application of the truth predicate to a sentence with a negated occurrence of the truth predicate, though the negation can be avoided by using the conditional. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 19.3) |
7485 | For Pythagoreans 'one' is not a number, but the foundation of numbers [Pythagoras, by Watson] |
Full Idea: For Pythagoreans, one, 1, is not a true number but the 'essence' of number, out of which the number system emerges. | |
From: report of Pythagoras (reports [c.530 BCE], Ch.8) by Peter Watson - Ideas Ch.8 | |
A reaction: I think this is right! Counting and numbers only arise once the concept of individuality and identity have arisen. Counting to one is no more than observing the law of identity. 'Two' is the big adventure. |
16321 | The compactness theorem can prove nonstandard models of PA [Halbach] |
Full Idea: Nonstandard models of Peano arithmetic are models of PA that are not isomorphic to the standard model. Their existence can be established with the compactness theorem or the adequacy theorem of first-order logic. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 8.3) |
16343 | The global reflection principle seems to express the soundness of Peano Arithmetic [Halbach] |
Full Idea: The global reflection principle ∀x(Sent(x) ∧ Bew[PA](x) → Tx) …seems to be the full statement of the soundness claim for Peano arithmetic, as it expresses that all theorems of Peano arithmetic are true. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 22.1) | |
A reaction: That is, an extra principle must be introduced to express the soundness. PA is, of course, not complete. |
16312 | To reduce PA to ZF, we represent the non-negative integers with von Neumann ordinals [Halbach] |
Full Idea: For the reduction of Peano Arithmetic to ZF set theory, usually the set of finite von Neumann ordinals is used to represent the non-negative integers. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 6) | |
A reaction: Halbach makes it clear that this is just one mode of reduction, relative interpretability. |
16308 | Set theory was liberated early from types, and recent truth-theories are exploring type-free [Halbach] |
Full Idea: While set theory was liberated much earlier from type restrictions, interest in type-free theories of truth only developed more recently. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 4) | |
A reaction: Tarski's theory of truth involves types (or hierarchies). |
15078 | There are levels of existence, as well as reality; objects exist at the lowest level in which they can function [Fine,K] |
Full Idea: Just as we recognise different levels of reality, so we should recognise different levels of existence. Each object will exist at the lowest level at which it can enjoy its characteristic form of life. | |
From: Kit Fine (Necessity and Non-Existence [2005], 10) | |
A reaction: I'm struggling with this claim, despite my sympathy for much of Fine's picture. I'm not sure that the so-called 'levels' of reality have different degrees of reality. |
16345 | That Peano arithmetic is interpretable in ZF set theory is taken by philosophers as a reduction [Halbach] |
Full Idea: The observation that Peano arithmetic is relatively interpretable in ZF set theory is taken by many philosophers to be a reduction of numbers to sets. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 23) | |
A reaction: Nice! Being able to express something in a different language is not the same as a reduction. Back to the drawing board. What do you really mean by a reduction? If we model something, we don't 'reduce' it to the model. |
15072 | Bottom level facts are subject to time and world, middle to world but not time, and top to neither [Fine,K] |
Full Idea: At the bottom are tensed or temporal facts, subject to the vicissitudes of time and hence of the world. Then come the timeless though worldly facts, subject to the world but not to time. Top are transcendental facts, subject to neither world nor time. | |
From: Kit Fine (Necessity and Non-Existence [2005], 08) | |
A reaction: For all of Fine's awesome grasp of logic and semantics, when he divides reality up as boldly as this I start to side a bit with the sceptics about modern metaphysics (like Ladyman and Ross). I daresay Fine acknowledges that it is 'speculative'. |
15071 | Tensed and tenseless sentences state two sorts of fact, which belong to two different 'realms' of reality [Fine,K] |
Full Idea: A tensed fact is stated by a tensed sentence while a tenseless fact is stated by a tenseless sentence, and they belong to two 'realms' of reality. That Socrates drank hemlock is in the temporal realm, while 2+2=4 is presumably in the timeless realm. | |
From: Kit Fine (Necessity and Non-Existence [2005], 07) | |
A reaction: Put so strongly, I suddenly find sales resistance to his proposal. All my instincts favour one realm, and I take 2+2=4 to be a highly general truth about that realm. It may be a truth of any possible realm, which would distinguish it. |
15075 | Modal features are not part of entities, because they are accounted for by the entity [Fine,K] |
Full Idea: It is natural to suggest that to be a man is to have certain kind of temporal-modal profile. ...but it seems natural that being a man accounts for the profile, ...so one should not appeal to an object's modal features in stating what the object is. | |
From: Kit Fine (Necessity and Non-Existence [2005], 09) | |
A reaction: This strikes me as a correct and very helpful point, as I am tempted to think that the modal dispositions of a thing are intrinsic to its identity. If we accept 'powers', must they be modal in character? Fine backs a sortal approach. That's ideology. |
15065 | What it is is fixed prior to existence or the object's worldly features [Fine,K] |
Full Idea: The identity of an object - what it is - is not a worldly matter; essence will precede existence in that the identity of an object may be fixed by its unworldly features even before any question of its existence or other worldly features is considered. | |
From: Kit Fine (Necessity and Non-Existence [2005], Intro) | |
A reaction: I'm not clear how this cashes out. If I remove the 'worldly features' of an object, what is there left which establishes identity? Fine carefully avoids talk of 'a priori' knowledge of identity. |
15076 | Essential features of an object have no relation to how things actually are [Fine,K] |
Full Idea: It is the core essential features of the object that will be independent of how things turn out, and they will be independent in the sense of holding regardless of circumstances, not whatever the circumstances. | |
From: Kit Fine (Necessity and Non-Existence [2005], 09) | |
A reaction: The distinction at the end seems to be that 'regardless' pays no attention to circumstances, whereas 'whatever' pays attention to all circumstances. In other words, essence has no relationship to how things are. Plausible. Nice to see 'core'. |
15073 | Self-identity should have two components, its existence, and its neutral identity with itself [Fine,K] |
Full Idea: The existential identity of an object with itself needs analysis into two components, one the neutral identity of the object with itself, and the other its existence. The existence of the object appears to be merely a gratuitous addition to its identity. | |
From: Kit Fine (Necessity and Non-Existence [2005], 08) | |
A reaction: This is at least a step towards clarification of the notion, which might be seen as just a way of asserting that something 'has an identity'. Fine likes the modern Fregean way of expressing this, as an equality relation. |
15074 | We would understand identity between objects, even if their existence was impossible [Fine,K] |
Full Idea: If there were impossible objects, ones that do not possibly exist, we would have no difficulty in understanding what it is for such objects to be identical or distinct than in the case of possible objects. | |
From: Kit Fine (Necessity and Non-Existence [2005], 08) | |
A reaction: Thus, a 'circular square' seems to be the same as a 'square circle'. Fine is arguing for identity to be independent of any questions of existence. |
16346 | Maybe necessity is a predicate, not the usual operator, to make it more like truth [Halbach] |
Full Idea: Should necessity be treated as a predicate rather than (as in modal logic) as a sentential operator? It is odd to assign different status to necessity and truth, hampering their interaction. That all necessities are true can't be expressed by an operator. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 24.2) | |
A reaction: [compressed] Halbach and Horsten consistently treat truth as a predicate, but maybe truth is an operator. Making necessity a predicate and not an operator would be a huge upheaval in the world of modal logic. Nice move! |
15064 | Proper necessary truths hold whatever the circumstances; transcendent truths regardless of circumstances [Fine,K] |
Full Idea: We distinguish between the necessary truths proper, those that hold whatever the circumstances, and the transcendent truths, those that hold regardless of the circumstances. | |
From: Kit Fine (Necessity and Non-Existence [2005], Intro) | |
A reaction: Fine's project seems to be dividing the necessities which derive from essence from the necessities which tended to be branded in essentialist discussions as 'trivial'. |
15070 | It is the nature of Socrates to be a man, so necessarily he is a man [Fine,K] |
Full Idea: It is of the nature of Socrates to be a man; and from this it appears to follow that necessarily he is a man. | |
From: Kit Fine (Necessity and Non-Existence [2005], 04) | |
A reaction: I'm always puzzled by this line of thought, because it is only the intrinsic nature of beings like Socrates which decides in the first place what a 'man' is. How can something help to create a category, and then necessarily belong to that category? |
15069 | Possible worlds may be more limited, to how things might actually turn out [Fine,K] |
Full Idea: An alternative conception of a possible world says it is constituted, not by the totality of facts, or of how things might be, but by the totality of circumstances, or how things might turn out. | |
From: Kit Fine (Necessity and Non-Existence [2005], 02) | |
A reaction: The general idea is to make a possible world more limited than in Idea 15068. It only contains properties arising from 'engagement with the world', and won't include timeless sentences. It is a bunch of possibilities, not of actualities? |
15068 | The actual world is a totality of facts, so we also think of possible worlds as totalities [Fine,K] |
Full Idea: We are accustomed think of the actual world as the totality of facts, and so we think of any possible world as being like the actual world in settling the truth-value of every single proposition. | |
From: Kit Fine (Necessity and Non-Existence [2005], 02) | |
A reaction: Hence it is normal to refer to a possible world as a 'maximal' set of of propositions (sentences, etc). See Idea 15069 for his proposed alternative view. |
16298 | We need propositions to ascribe the same beliefs to people with different languages [Halbach] |
Full Idea: Being able to ascribe the same proposition as a belief to persons who do not have a common language seems to be one of the main reasons to employ propositions. | |
From: Volker Halbach (Axiomatic Theories of Truth [2011], 2) | |
A reaction: Propositions concern beliefs, as well as sentence meanings. I would want to say that a dog and I could believe the same thing, and that is a non-linguistic reason to believe in propositions. Maybe 'translation' cuts out the proposition middleman? |
3053 | Pythagoras taught that virtue is harmony, and health, and universal good, and God [Pythagoras, by Diog. Laertius] |
Full Idea: Pythagoras taught that virtue is harmony, and health, and universal good, and God. | |
From: report of Pythagoras (reports [c.530 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 08.1.19 | |
A reaction: I like the link with health, because I consider that a bridge over the supposed fact-value gap. Very Pythagorean to think that virtue is harmony. Plato liked that thought. |
5244 | For Pythagoreans, justice is simply treating all people the same [Pythagoras, by Aristotle] |
Full Idea: Some even think that what is just is simple reciprocity, as the Pythagoreans maintained, because they defined justice simply as having done to one what one has done to another. | |
From: report of Pythagoras (reports [c.530 BCE], 28) by Aristotle - Nicomachean Ethics 1132b22 | |
A reaction: One wonders what Pythagoreans made of slavery. Aristotle argues that officials, for example, have superior rights. The Pythagorean idea makes fairness the central aspect of justice, and that must at least be partly right. |
553 | Pythagoreans think mathematical principles are the principles of all of nature [Pythagoras, by Aristotle] |
Full Idea: The Pythagoreans thought that the principles of mathematical entities were the principles of all entities. | |
From: report of Pythagoras (reports [c.530 BCE]) by Aristotle - Metaphysics 985b |
554 | Pythagoreans say things imitate numbers, but Plato says things participate in numbers [Pythagoras, by Aristotle] |
Full Idea: Pythagoreans said that entities existed by imitation of the numbers, whereas Plato said that it was by participation. | |
From: report of Pythagoras (reports [c.530 BCE]) by Aristotle - Metaphysics 987b |
375 | When musical harmony and rhythm were discovered, similar features were seen in bodily movement [Pythagoras, by Plato] |
Full Idea: When our predecessors discovered musical scales, they also discovered similar features in bodily movement, which should also be measured numerically, and called 'tempos' and 'measures'. | |
From: report of Pythagoras (reports [c.530 BCE]) by Plato - Philebus 17d |
638 | Pythagoreans define timeliness, justice and marriage in terms of numbers [Pythagoras, by Aristotle] |
Full Idea: The Pythagoreans offered definitions of a limited range of things on the basis of numbers; examples are timeliness, justice and marriage. | |
From: report of Pythagoras (reports [c.530 BCE]) by Aristotle - Metaphysics 1078b |
644 | For Pythagoreans the entire universe is made of numbers [Pythagoras, by Aristotle] |
Full Idea: For Pythagoreans the entire universe is constructed of numbers. | |
From: report of Pythagoras (reports [c.530 BCE]) by Aristotle - Metaphysics 1080b |
15067 | A-theorists tend to reject the tensed/tenseless distinction [Fine,K] |
Full Idea: Most A-theorists have been inclined to reject the tensed/tenseless distinction. | |
From: Kit Fine (Necessity and Non-Existence [2005], 01) | |
A reaction: Presumably this is because they reject the notion of 'tenseless' truths. But sentences like 'two and two make four' seem not to be very tensy. |
15077 | It is said that in the A-theory, all existents and objects must be tensed, as well as the sentences [Fine,K] |
Full Idea: It is said that there is no room in the A-theorists' ontology for a realm of timeless existents. Just as there is a tendency to think that every sentence is tensed, so there is a tendency to think that every object must enjoy a tensed form of existence. | |
From: Kit Fine (Necessity and Non-Existence [2005], 10) | |
A reaction: Fine is arguing for certain things to exist or be true independently of time (such as arithmetic, or essential identities). I struggle with the notion of timeless existence. |
15066 | B-theorists say tensed sentences have an unfilled argument-place for a time [Fine,K] |
Full Idea: B-theorists regard tensed sentences as incomplete expressions, implicitly containing an unfilled argument-place for the time at which they are to be evaluated. | |
From: Kit Fine (Necessity and Non-Existence [2005], 01) | |
A reaction: To distinguish past from future it looks as if you would need two argument-places, not one. Then there are 'used to be' and 'had been' to evaluate. |
7467 | The modern idea of an immortal soul was largely created by Pythagoras [Pythagoras, by Watson] |
Full Idea: The modern concept of the immortal soul is a Greek idea, which owes much to Pythagoras. | |
From: report of Pythagoras (reports [c.530 BCE]) by Peter Watson - Ideas Ch.5 | |
A reaction: You can see why it caught on - it is a very appealing idea. Watson connects the 'modern' view with the ideas of heaven and hell. Obviously the idea of an afterlife goes a long way back (judging from the contents of ancient graves). |