93 ideas
| 19693 | There is practical wisdom (for action), and theoretical wisdom (for deep understanding) [Aristotle, by Whitcomb] |
| Full Idea: Aristotle takes wisdom to come in two forms, the practical and the theoretical, the former of which is good judgement about how to act, and the latter of which is deep knowledge or understanding. | |
| From: report of Aristotle (works [c.330 BCE]) by Dennis Whitcomb - Wisdom Intro | |
| A reaction: The interesting question is then whether the two are connected. One might be thoroughly 'sensible' about action, without counting as 'wise', which seems to require a broader view of what is being done. Whitcomb endorses Aristotle on this idea. |
| 13310 | Wisdom does not lie in books, and unread people can also become wise [Seneca] |
| Full Idea: What grounds could I possibly have for supposing that a person who has no acquaintance with books will never be a wise man? For wisdom does not lie in books. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
| A reaction: A useful warning to the likes of me, who may have retreated from the hurly-burly of the agora (see Callicles in Plato's 'Gorgias'), under the illusion that detachment is needed for wisdom. Maybe involvement is needed for wisdom. |
| 13295 | Wise people escape necessity by willing it [Seneca] |
| Full Idea: There is nothing a wise man does reluctantly; he escapes necessity because he wills what necessity is going to force on him. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 054) | |
| A reaction: He is discussing death in this letter. The difficulty here is sliding into fatalism. For instance, if you are informed that you have cancer, it is tempting to become 'wise' and will your own death, but lots of people fight it, and win. |
| 13317 | Philosophy aims at happiness [Seneca] |
| Full Idea: Philosophy takes as her aim the state of happiness. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 090) | |
| A reaction: A startlingly forthright view. It seems to neglect what I take to be the main aim of philosophy, which is to achieve understanding. I presume true happiness would follow from that. Seneca must now explain why soporific pleasure is wrong. |
| 13293 | What philosophy offers humanity is guidance [Seneca] |
| Full Idea: Shall I tell you what philosophy holds out for humanity? Counsel. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 048) | |
| A reaction: See Quine for a flat modern denial of this claim (Idea 9764). There is a modern tendency to see ethics and political thought operating at a meta- or metameta- level. I take the main ethical theories to be very illuminating of real life. |
| 13309 | That something is a necessary condition of something else doesn't mean it caused it [Seneca] |
| Full Idea: There's no reason for you to assume that, X being something without which Y could never have come about, Y came about as a result of the assistance of X. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
| A reaction: This thought originates with Carneades, reported by Cicero. This is a clear message to the likes of Mackie, who are in danger of thinking that giving the preconditions of something is sufficient to give its causes. |
| 13313 | Even philosophers have got bogged down in analysing tiny bits of language [Seneca] |
| Full Idea: Even the philosophers have descended to the level of drawing distinctions between the uses of different syllables and discussing the proper meanings of prepositions and conjunctions. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
| A reaction: How wonderfully prescient! The vast industry of modern philosophy of language exactly fits Seneca's description. I don't quite share his contempt, of course, and I think Seneca would have a bit of sympathy with modern analysis (just a bit!). |
| 1575 | For Aristotle logos is essentially the ability to talk rationally about questions of value [Roochnik on Aristotle] |
| Full Idea: For Aristotle logos is the ability to speak rationally about, with the hope of attaining knowledge, questions of value. | |
| From: comment on Aristotle (works [c.330 BCE]) by David Roochnik - The Tragedy of Reason p.26 |
| 1589 | Aristotle is the supreme optimist about the ability of logos to explain nature [Roochnik on Aristotle] |
| Full Idea: Aristotle is the great theoretician who articulates a vision of a world in which natural and stable structures can be rationally discovered. His is the most optimistic and richest view of the possibilities of logos | |
| From: comment on Aristotle (works [c.330 BCE]) by David Roochnik - The Tragedy of Reason p.95 |
| 8200 | Aristotelian definitions aim to give the essential properties of the thing defined [Aristotle, by Quine] |
| Full Idea: A real definition, according to the Aristotelian tradition, gives the essence of the kind of thing defined. Man is defined as a rational animal, and thus rationality and animality are of the essence of each of us. | |
| From: report of Aristotle (works [c.330 BCE]) by Willard Quine - Vagaries of Definition p.51 | |
| A reaction: Compare Idea 4385. Personally I prefer the Aristotelian approach, but we may have to say 'We cannot identify the essence of x, and so x cannot be defined'. Compare 'his mood was hard to define' with 'his mood was hostile'. |
| 4385 | Aristotelian definition involves first stating the genus, then the differentia of the thing [Aristotle, by Urmson] |
| Full Idea: For Aristotle, to give a definition one must first state the genus and then the differentia of the kind of thing to be defined. | |
| From: report of Aristotle (works [c.330 BCE]) by J.O. Urmson - Aristotle's Doctrine of the Mean p.157 | |
| A reaction: Presumably a modern definition would just be a list of properties, but Aristotle seeks the substance. How does he define a genus? - by placing it in a further genus? |
| 16295 | Tarski proved that truth cannot be defined from within a given theory [Tarski, by Halbach] |
| Full Idea: Tarski's Theorem states that under fairly generally applicable conditions, the assumption that there is a definition of truth within a given theory for the language of that same theory leads to a contradiction. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Volker Halbach - Axiomatic Theories of Truth 1 | |
| A reaction: That might leave room for a definition outside the given theory. I take the main motivation for the axiomatic approach to be a desire to get a theory of truth within the given theory, where Tarski's Theorem says traditional approaches are just wrong. |
| 15342 | Tarski proved that any reasonably expressive language suffers from the liar paradox [Tarski, by Horsten] |
| Full Idea: Tarski's Theorem on the undefinability of truth says in a language sufficiently rich to talk about itself (which Gödel proved possible, via coding) the liar paradox can be carried out. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Leon Horsten - The Tarskian Turn 02.2 | |
| A reaction: The point is that truth is formally indefinable if it leads inescapably to contradiction, which the liar paradox does. This theorem is the motivation for all modern attempts to give a rigorous account of truth. |
| 19069 | 'True sentence' has no use consistent with logic and ordinary language, so definition seems hopeless [Tarski] |
| Full Idea: The possibility of a consistent use of 'true sentence' which is in harmony with the laws of logic and the spirit of everyday language seems to be very questionable, so the same doubt attaches to the possibility of constructing a correct definition. | |
| From: Alfred Tarski (The Concept of Truth for Formalized Languages [1933], §1) | |
| A reaction: This is often cited as Tarski having conclusively proved that 'true' cannot be defined from within a language, but his language here is much more circumspect. Modern critics say the claim depends entirely on classical logic. |
| 16296 | Tarski's Theorem renders any precise version of correspondence impossible [Tarski, by Halbach] |
| Full Idea: Tarski's Theorem applies to any sufficient precise version of the correspondence theory of truth, and all the other traditional theories of truth. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Volker Halbach - Axiomatic Theories of Truth 1 | |
| A reaction: This is the key reason why modern thinkers have largely dropped talk of the correspondence theory. See Idea 16295. |
| 10672 | Tarskian semantics says that a sentence is true iff it is satisfied by every sequence [Tarski, by Hossack] |
| Full Idea: Tarskian semantics says that a sentence is true iff it is satisfied by every sequence, where a sequence is a set-theoretic individual, a set of ordered pairs each with a natural number as its first element and an object from the domain for its second. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Keith Hossack - Plurals and Complexes 3 |
| 15339 | Tarski gave up on the essence of truth, and asked how truth is used, or how it functions [Tarski, by Horsten] |
| Full Idea: Tarski emancipated truth theory from traditional philosophy, by no longer posing Pilate's question (what is truth? or what is the essence of truth?) but instead 'how is truth used?', 'how does truth function?' and 'how can its functioning be described?'. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Leon Horsten - The Tarskian Turn 02.2 | |
| A reaction: Horsten, later in the book, does not give up on the essence of truth, and modern theorists are trying to get back to that question by following Tarski's formal route. Modern analytic philosophy at its best, it seems to me. |
| 16302 | Tarski did not just aim at a definition; he also offered an adequacy criterion for any truth definition [Tarski, by Halbach] |
| Full Idea: Tarski did not settle for a definition of truth, taking its adequacy for granted. Rather he proposed an adequacy criterion for evaluating the adequacy of definitions of truth. The criterion is his famous Convention T. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Volker Halbach - Axiomatic Theories of Truth 3 | |
| A reaction: Convention T famously says the sentence is true if and only if a description of the sentence is equivalent to affirming the sentence. 'Snow is white' iff snow is white. |
| 19135 | Tarski enumerates cases of truth, so it can't be applied to new words or languages [Davidson on Tarski] |
| Full Idea: Tarski does not tell us how to apply his concept of truth to a new case, whether the new case is a new language or a word newly added to a language. This is because enumerating cases gives no clue for the next or general case. | |
| From: comment on Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Donald Davidson - Truth and Predication 1 | |
| A reaction: His account has been compared to a telephone directory. We aim to understand the essence of anything, so that we can fully know it, and explain and predict how it will behave. Either truth is primitive, or I demand to know its essence. |
| 19138 | Tarski define truths by giving the extension of the predicate, rather than the meaning [Davidson on Tarski] |
| Full Idea: Tarski defined the class of true sentences by giving the extension of the truth predicate, but he did not give the meaning. | |
| From: comment on Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Donald Davidson - Truth and Predication 1 | |
| A reaction: This is analogous to giving an account of the predicate 'red' as the set of red objects. Since I regard that as a hopeless definition of 'red', I am inclined to think the same of Tarski's account of truth. It works in the logic, but so what? |
| 4699 | Tarski made truth relative, by only defining truth within some given artificial language [Tarski, by O'Grady] |
| Full Idea: Tarski's account doesn't hold for natural languages. The general notion of truth is replaced by "true-in-L", where L is a formal language. Hence truth is relativized to each artificial language. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Paul O'Grady - Relativism Ch.2 | |
| A reaction: This is a pretty good indication that Tarski's theory is NOT a correspondence theory, even if its structure may sometimes give that impression. |
| 19324 | Tarski has to avoid stating how truths relate to states of affairs [Kirkham on Tarski] |
| Full Idea: Tarski has to define truths so as not to make explicit the relation between a true sentence and an obtaining state of affairs. ...He has to list each sentence separately, and simply assign it a state of affairs. | |
| From: comment on Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Richard L. Kirkham - Theories of Truth: a Critical Introduction 5.8 | |
| A reaction: He has to avoid semantic concepts like 'reference', because he wants a physicalist theory, according to Kirkham. Thus the hot interest in theories of reference in the 1970s/80s. And also attempts to give a physicalist account of meaning. |
| 15410 | Truth only applies to closed formulas, but we need satisfaction of open formulas to define it [Burgess on Tarski] |
| Full Idea: In Tarski's theory of truth, although the notion of truth is applicable only to closed formulas, to define it we must define a more general notion of satisfaction applicable to open formulas. | |
| From: comment on Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by John P. Burgess - Philosophical Logic 1.8 | |
| A reaction: This is a helpful pointer to what is going on in the Tarski definition. It culminates in the 'satisfaction of all sequences', which presumable delivers the required closed formula. |
| 18811 | Tarski uses sentential functions; truly assigning the objects to variables is what satisfies them [Tarski, by Rumfitt] |
| Full Idea: Tarski invoked the notion of a sentential function, where components are replaced by appropriate variables. A function is then satisfied by assigning objects to variables. An assignment satisfies if the function is true of the things assigned. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Ian Rumfitt - The Boundary Stones of Thought 3.2 | |
| A reaction: [very compressed] This use of sentential functions, rather than sentences, looks like the key to Tarski's definition of truth. |
| 15365 | We can define the truth predicate using 'true of' (satisfaction) for variables and some objects [Tarski, by Horsten] |
| Full Idea: The truth predicate, says Tarski, should be defined in terms of the more primitive satisfaction relation: the relation of being 'true of'. The fundamental notion is a formula (containing the free variables) being true of a sequence of objects as values. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Leon Horsten - The Tarskian Turn 06.3 |
| 19314 | For physicalism, reduce truth to satisfaction, then define satisfaction as physical-plus-logic [Tarski, by Kirkham] |
| Full Idea: Tarski, a physicalist, reduced semantics to physical and/or logicomathematical concepts. He defined all semantic concepts, save satisfaction, in terms of truth. Then truth is defined in terms of satisfaction, and satisfaction is given non-semantically. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Richard L. Kirkham - Theories of Truth: a Critical Introduction 5.1 | |
| A reaction: The term 'logicomathematical' is intended to cover set theory. Kirkham says you can remove these restrictions from Tarski's theory, and the result is a version of the correspondence theory. |
| 19316 | Insight: don't use truth, use a property which can be compositional in complex quantified sentence [Tarski, by Kirkham] |
| Full Idea: Tarski's great insight is find another property, since open sentences are not truth. It must be had by open and genuine sentences. Clauses having it must generate it for the whole sentence. Truth can be defined for sentences by using it. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Richard L. Kirkham - Theories of Truth: a Critical Introduction 5.4 | |
| A reaction: The proposed property is 'satisfaction', which can (unlike truth) be a feature open sentences (such as 'x is green', which is satisfied by x='grass'), |
| 19175 | Tarski gave axioms for satisfaction, then derived its explicit definition, which led to defining truth [Tarski, by Davidson] |
| Full Idea: Tarski turned his axiomatic characterisation of satisfaction into an explicit definition of the satisfaction-predicate using some fancy set theoretical apparatus, and this in turn leads to the explicit definition of the truth predicate. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Donald Davidson - Truth and Predication 7 |
| 16303 | Tarski made truth respectable, by proving that it could be defined [Tarski, by Halbach] |
| Full Idea: Tarski's proof of the definability of truth allowed him to establish truth as a respectable notion by his standards. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Volker Halbach - Axiomatic Theories of Truth 3 |
| 19134 | Tarski defined truth for particular languages, but didn't define it across languages [Davidson on Tarski] |
| Full Idea: Tarski defined various predicates of the form 's is true in L', each applicable to a single language, but he failed to define a predicate of the form 's is true in L' for variable 'L'. | |
| From: comment on Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Donald Davidson - Truth and Predication 1 | |
| A reaction: You might say that no one defines 'tree' to be just 'in English', but we might define 'multiplies' to be in Peano Arithmetic. This indicates the limited and formal nature of what Tarski was trying to achieve. |
| 16304 | Tarski didn't capture the notion of an adequate truth definition, as Convention T won't prove non-contradiction [Halbach on Tarski] |
| Full Idea: Every really adequate theory of truth should also prove the law of non-contradiction. Therefore Tarski's notion of adequacy in Convention T fails to capture the intuitive notion of adequacy he is after. | |
| From: comment on Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Volker Halbach - Axiomatic Theories of Truth 3 | |
| A reaction: Tarski points out this weakness, in a passage quoted by Halbach. This obviously raises the question of what truth theories should prove, and this is explored by Halbach. If they start to prove arithmetic, we get nervous. Non-contradiction and x-middle? |
| 2571 | Tarski says that his semantic theory of truth is completely neutral about all metaphysics [Tarski, by Haack] |
| Full Idea: Tarski says "we may remain naïve realists or idealists, empiricists or metaphysicians… The semantic conception is completely neutral toward all these issues." | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Susan Haack - Philosophy of Logics 7.5 |
| 10821 | Physicalists should explain reference nonsemantically, rather than getting rid of it [Tarski, by Field,H] |
| Full Idea: Tarski work was to persuade physicalist that eliminating semantics was on the wrong track, and that we should explicate notions in the theory of reference nonsemantically rather than simply get rid of them. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Hartry Field - Tarski's Theory of Truth §3 |
| 10822 | A physicalist account must add primitive reference to Tarski's theory [Field,H on Tarski] |
| Full Idea: We need to add theories of primitive reference to Tarski's account if we are to establish the notion of truth as a physicalistically acceptable notion. | |
| From: comment on Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Hartry Field - Tarski's Theory of Truth §4 | |
| A reaction: This is the main point of Field's paper, and sounds very plausible to me. There is something major missing from Tarski, and at some point there needs to be a 'primitive' notion of thought and language making contact with the world, as it can't be proved. |
| 10969 | Tarski had a theory of truth, and a theory of theories of truth [Tarski, by Read] |
| Full Idea: Besides a theory of truth of his own, Tarski developed a theory of theories of truth. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Stephen Read - Thinking About Logic Ch.1 | |
| A reaction: The famous snow biconditional is the latter, and the recursive account based on satisfaction is the former. |
| 17746 | Tarski's 'truth' is a precise relation between the language and its semantics [Tarski, by Walicki] |
| Full Idea: Tarski's analysis of the concept of 'truth' ...is given a precise treatment as a particular relation between syntax (language) and semantics (the world). | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Michal Walicki - Introduction to Mathematical Logic History E.1 | |
| A reaction: My problem is that the concept of truth seems to apply to animal minds, which are capable of making right or wrong judgements, and of realising their errors. Tarski didn't make universal claims for his account. |
| 10904 | Tarskian truth neglects the atomic sentences [Mulligan/Simons/Smith on Tarski] |
| Full Idea: The Tarskian account of truth neglects the atomic sentences. | |
| From: comment on Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Mulligan/Simons/Smith - Truth-makers §1 | |
| A reaction: Yes! The whole Tarskian edifice is built on a foundation which it is taboo even to mention. If truth is just the assignment of 'T' and 'F', that isn't even the beginnings of a theory of 'truth'. |
| 15322 | Tarski's had the first axiomatic theory of truth that was minimally adequate [Tarski, by Horsten] |
| Full Idea: Tarski's work is the earliest axiomatic theory of truth that meets minimal adequacy conditions. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Leon Horsten - The Tarskian Turn 01.1 | |
| A reaction: This shows a way in which Tarski gave a new direction to the study of truth. Subsequent theories have been 'stronger'. |
| 16306 | Tarski defined truth, but an axiomatisation can be extracted from his inductive clauses [Tarski, by Halbach] |
| Full Idea: Tarski preferred a definition of truth, but from that an axiomatisation can be extracted. His induction clauses can be turned into axioms. Hence he opened the way to axiomatic theories of truth. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Volker Halbach - Axiomatic Theories of Truth 3 |
| 13282 | Aristotle relativises the notion of wholeness to different measures [Aristotle, by Koslicki] |
| Full Idea: Aristotle proposes to relativise unity and plurality, so that a single object can be both one (indivisible) and many (divisible) simultaneously, without contradiction, relative to different measures. Wholeness has degrees, with the strength of the unity. | |
| From: report of Aristotle (works [c.330 BCE]) by Kathrin Koslicki - The Structure of Objects 7.2.12 | |
| A reaction: [see Koslicki's account of Aristotle for details] As always, the Aristotelian approach looks by far the most promising. Simplistic mechanical accounts of how parts make wholes aren't going to work. We must include the conventional and conceptual bit. |
| 18759 | Identity is invariant under arbitrary permutations, so it seems to be a logical term [Tarski, by McGee] |
| Full Idea: Tarski showed that the only binary relations invariant under arbitrary permutations are the universal relation, the empty relation, identity and non-identity, thus giving us a reason to include '=' among the logical terms. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Vann McGee - Logical Consequence 6 | |
| A reaction: Tarski was looking for a criterion to distinguish logical from non-logical terms, since his account of logical validity depended on it. This idea lies behind whether a logic is or is not specified to be 'with identity' (i.e. using '='). |
| 4730 | For Aristotle, the subject-predicate structure of Greek reflected a substance-accident structure of reality [Aristotle, by O'Grady] |
| Full Idea: Aristotle apparently believed that the subject-predicate structure of Greek reflected the substance-accident nature of reality. | |
| From: report of Aristotle (works [c.330 BCE]) by Paul O'Grady - Relativism Ch.4 | |
| A reaction: We need not assume that Aristotle is wrong. It is a chicken-and-egg. There is something obvious about subject-predicate language, if one assumes that unified objects are part of nature, and not just conventional. |
| 10823 | A name denotes an object if the object satisfies a particular sentential function [Tarski] |
| Full Idea: To say that the name x denotes a given object a is the same as to stipulate that the object a ... satisfies a sentential function of a particular type. | |
| From: Alfred Tarski (The Concept of Truth for Formalized Languages [1933], p.194) |
| 18756 | Tarski built a compositional semantics for predicate logic, from dependent satisfactions [Tarski, by McGee] |
| Full Idea: Tarski discovered how to give a compositional semantics for predicate calculus, defining truth in terms of satisfaction, and showing how satisfaction for a complicated formula depends on satisfaction of the simple subformulas. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Vann McGee - Logical Consequence 4 | |
| A reaction: The problem was that the subformulas may contain free variables, and thus not be sentences with truth values. 'Satisfaction' can handle this, where 'truth' cannot (I think). |
| 19313 | Tarksi invented the first semantics for predicate logic, using this conception of truth [Tarski, by Kirkham] |
| Full Idea: Tarski invented a formal semantics for quantified predicate logic, the logic of reasoning about mathematics. The heart of this great accomplishment is his theory of truth. It has been called semantic 'theory' of truth, but Tarski preferred 'conception'. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Richard L. Kirkham - Theories of Truth: a Critical Introduction 5.1 |
| 16323 | The object language/ metalanguage distinction is the basis of model theory [Tarski, by Halbach] |
| Full Idea: Tarski's distinction between object and metalanguage forms the basis of model theory. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Volker Halbach - Axiomatic Theories of Truth 11 |
| 8940 | Tarski avoids the Liar Paradox, because truth cannot be asserted within the object language [Tarski, by Fisher] |
| Full Idea: In Tarski's account of truth, self-reference (as found in the Liar Paradox) is prevented because the truth predicate for any given object language is never a part of that object language, and so a sentence can never predicate truth of itself. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Jennifer Fisher - On the Philosophy of Logic 03.I | |
| A reaction: Thus we solve the Liar Paradox by ruling that 'you are not allowed to say that'. Hm. The slightly odd result is that in any conversation about whether p is true, we end up using (logically speaking) two different languages simultaneously. Hm. |
| 10154 | Tarski's theory of truth shifted the approach away from syntax, to set theory and semantics [Feferman/Feferman on Tarski] |
| Full Idea: Tarski's theory of truth has been most influential in eventually creating a shift from the entirely syntactic way of doing things in metamathematics (promoted by Hilbert in the 1920s, in his theory of proofs), towards a set-theoretical, semantic approach. | |
| From: comment on Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Feferman / Feferman - Alfred Tarski: life and logic Int III |
| 13276 | The unmoved mover and the soul show Aristotelian form as the ultimate mereological atom [Aristotle, by Koslicki] |
| Full Idea: Aristotle's discussion of the unmoved mover and of the soul confirms the suspicion that form, when it is not thought of as the object represented in a definition, plays the role of the ultimate mereological atom within his system. | |
| From: report of Aristotle (works [c.330 BCE]) by Kathrin Koslicki - The Structure of Objects 6.6 | |
| A reaction: Aristotle is concerned with which things are 'divisible', and he cites these two examples as indivisible, but they may be too unusual to offer an actual theory of how Aristotle builds up wholes from atoms. He denies atoms in matter. |
| 13277 | The 'form' is the recipe for building wholes of a particular kind [Aristotle, by Koslicki] |
| Full Idea: Thus in Aristotle we may think of an object's formal components as a sort of recipe for how to build wholes of that particular kind. | |
| From: report of Aristotle (works [c.330 BCE]) by Kathrin Koslicki - The Structure of Objects 7.2.5 | |
| A reaction: In the elusive business of pinning down what Aristotle means by the crucial idea of 'form', this analogy strikes me as being quite illuminating. It would fit DNA in living things, and the design of an artifact. |
| 5991 | For Aristotle, knowledge is of causes, and is theoretical, practical or productive [Aristotle, by Code] |
| Full Idea: Aristotle thinks that in general we have knowledge or understanding when we grasp causes, and he distinguishes three fundamental types of knowledge - theoretical, practical and productive. | |
| From: report of Aristotle (works [c.330 BCE]) by Alan D. Code - Aristotle | |
| A reaction: Productive knowledge we tend to label as 'knowing how'. The centrality of causes for knowledge would get Aristotle nowadays labelled as a 'naturalist'. It is hard to disagree with his three types, though they may overlap. |
| 11239 | The notion of a priori truth is absent in Aristotle [Aristotle, by Politis] |
| Full Idea: The notion of a priori truth is conspicuously absent in Aristotle. | |
| From: report of Aristotle (works [c.330 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 1.5 | |
| A reaction: Cf. Idea 11240. |
| 23312 | Aristotle is a rationalist, but reason is slowly acquired through perception and experience [Aristotle, by Frede,M] |
| Full Idea: Aristotle is a rationalist …but reason for him is a disposition which we only acquire over time. Its acquisition is made possible primarily by perception and experience. | |
| From: report of Aristotle (works [c.330 BCE]) by Michael Frede - Aristotle's Rationalism p.173 | |
| A reaction: I would describe this process as the gradual acquisition of the skill of objectivity, which needs the right knowledge and concepts to evaluate new experiences. |
| 16111 | Aristotle wants to fit common intuitions, and therefore uses language as a guide [Aristotle, by Gill,ML] |
| Full Idea: Since Aristotle generally prefers a metaphysical theory that accords with common intuitions, he frequently relies on facts about language to guide his metaphysical claims. | |
| From: report of Aristotle (works [c.330 BCE]) by Mary Louise Gill - Aristotle on Substance Ch.5 | |
| A reaction: I approve of his procedure. I take intuition to be largely rational justifications too complex for us to enunciate fully, and language embodies folk intuitions in its concepts (especially if the concepts occur in many languages). |
| 16971 | Plato says sciences are unified around Forms; Aristotle says they're unified around substance [Aristotle, by Moravcsik] |
| Full Idea: Plato's unity of science principle states that all - legitimate - sciences are ultimately about the Forms. Aristotle's principle states that all sciences must be, ultimately, about substances, or aspects of substances. | |
| From: report of Aristotle (works [c.330 BCE], 1) by Julius Moravcsik - Aristotle on Adequate Explanations 1 |
| 11243 | Aristotelian explanations are facts, while modern explanations depend on human conceptions [Aristotle, by Politis] |
| Full Idea: For Aristotle things which explain (the explanantia) are facts, which should not be associated with the modern view that says explanations are dependent on how we conceive and describe the world (where causes are independent of us). | |
| From: report of Aristotle (works [c.330 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 2.1 | |
| A reaction: There must be some room in modern thought for the Aristotelian view, if some sort of robust scientific realism is being maintained against the highly linguistic view of philosophy found in the twentieth century. |
| 13297 | To the four causes Plato adds a fifth, the idea which guided the event [Seneca] |
| Full Idea: To the four Aristotelian causes Plato adds a fifth in the model - what he himself calls the 'idea' - this being what the sculptor had constantly before his eyes as he executed the intended work. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 065) | |
| A reaction: A very interesting interpretation. I take the four 'causes' to be primarily the four 'explanations', and it exactly fits how we should understand Plato, as offer a crucial underlying explanation. The statue is Aristotle's example. |
| 3320 | Aristotle's standard analysis of species and genus involves specifying things in terms of something more general [Aristotle, by Benardete,JA] |
| Full Idea: The standard Aristotelian doctrine of species and genus in the theory of anything whatever involves specifying what the thing is in terms of something more general. | |
| From: report of Aristotle (works [c.330 BCE]) by José A. Benardete - Metaphysics: the logical approach Ch.10 |
| 12000 | Aristotle regularly says that essential properties explain other significant properties [Aristotle, by Kung] |
| Full Idea: The view that essential properties are those in virtue of which other significant properties of the subjects under investigation can be explained is encountered repeatedly in Aristotle's work. | |
| From: report of Aristotle (works [c.330 BCE]) by Joan Kung - Aristotle on Essence and Explanation IV | |
| A reaction: What does 'significant' mean here? I take it that the significant properties are the ones which explain the role, function and powers of the object. |
| 13307 | If everything can be measured, try measuring the size of a man's soul [Seneca] |
| Full Idea: Nothing's outside your scope when it comes to measurement. Well, if you're such an expert, measure a man's soul; tell me how large or how small that is. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
| A reaction: This is Descartes's non-spatial argument, which I take to be one of the four main props to his mind-body dualism. As always, it is expressed with beautiful concision by Seneca. |
| 23300 | Aristotle and the Stoics denied rationality to animals, while Platonists affirmed it [Aristotle, by Sorabji] |
| Full Idea: Aristotle, and also the Stoics, denied rationality to animals. …The Platonists, the Pythagoreans, and some more independent Aristotelians, did grant reason and intellect to animals. | |
| From: report of Aristotle (works [c.330 BCE]) by Richard Sorabji - Rationality 'Denial' | |
| A reaction: This is not the same as affirming or denying their consciousness. The debate depends on how rationality is conceived. |
| 21399 | Referring to a person, and speaking about him, are very different [Seneca] |
| Full Idea: It makes a very great difference whether you refer to the person directly, or speak about him. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 117.13), quoted by A.A. Long - Hellenistic Philosophy 4.3.2 | |
| A reaction: We seem to think that the distinctiveness of reference was first spotted by Frege. Not so. |
| 11240 | The notion of analytic truth is absent in Aristotle [Aristotle, by Politis] |
| Full Idea: The notion of analytic truth is conspicuously absent in Aristotle. | |
| From: report of Aristotle (works [c.330 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 1.5 | |
| A reaction: Cf. Idea 11239. |
| 20407 | Taste is the capacity to judge an object or representation which is thought to be beautiful [Tarski, by Schellekens] |
| Full Idea: Taste is the faculty for judging an object or a kind of representation through a satisfaction or a dissatisfaction, ...where the object of such a satisfaction is called beautiful. | |
| From: report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Elizabeth Schellekens - Immanuel Kant (aesthetics) 1 | |
| A reaction: We usually avoid the word 'faculty' nowadays, because it implies a specific mechanism, but 'capacity' will do. Kant is said to focus specifically on beauty, whereas modern aestheticians have a broader view of the type of subject matter. |
| 6559 | Aristotle never actually says that man is a rational animal [Aristotle, by Fogelin] |
| Full Idea: To the best of my knowledge (and somewhat to my surprise), Aristotle never actually says that man is a rational animal; however, he all but says it. | |
| From: report of Aristotle (works [c.330 BCE]) by Robert Fogelin - Walking the Tightrope of Reason Ch.1 | |
| A reaction: When I read this I thought that this database would prove Fogelin wrong, but it actually supports him, as I can't find it in Aristotle either. Descartes refers to it in Med.Two. In Idea 5133 Aristotle does say that man is a 'social being'. But 22586! |
| 13325 | Trouble in life comes from copying other people, which is following convention instead of reason [Seneca] |
| Full Idea: One of the causes of the troubles that beset us is the way our lives are guided by the example of others; instead of being set to rights by reason we're seduced by convention. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 123) | |
| A reaction: An interesting practical spin and critique of the standard metaethical idea that morality is just convention. If you think morality is convention, presumably your moral duty is to imitate your neighbours. Nice deconstruction. |
| 22239 | Humans acquired the concept of virtue from an analogy with bodily health and strength [Seneca, by Allen] |
| Full Idea: Seneca held that human beings owe the original acquisition of the concept of virtue to an analogy with bodily health and strength | |
| From: report of Seneca the Younger (Letters from a Stoic [c.60], 120.5) by James Allen - Soul's Virtue and the Health of the Body p.76 | |
| A reaction: This is an unusual view, even for a stoic, but shows how close the concepts of health and virtue were. Notice that it is strength as well as health. Plato just emphasises mental and physical harmony. |
| 13294 | We know death, which is like before birth; ceasing to be and never beginning are the same [Seneca] |
| Full Idea: I already know what death is like - it will be the same after me as it was before me. ..Only an utter idiot would think a lamp was worse off when it was put out than before it was lit. ..What does it matter whether you cease to be or never begin? | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 054) | |
| A reaction: These sentiments are, interestingly, derived from the epicureans, rather than from the stoic tradition, but to us they probably look close together, where they looked like opponents at the time. |
| 13299 | Living is nothing wonderful; what matters is to die well [Seneca] |
| Full Idea: There's nothing so very great about living - all your slaves and all the animals do it. What is, however, a great thing is to die in a manner which is honourable, enlightened and courageous. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 077) | |
| A reaction: You get the feeling that Seneca actually thought suicide was better than a natural death. Did he actually seek his own death? It is an odd interpretation of his own stoic injunction to 'live according to nature'. |
| 13300 | It is as silly to lament ceasing to be as to lament not having lived in the remote past [Seneca] |
| Full Idea: Wouldn't you think a man a prize fool if he burst into tears because he didn't live a thousand years ago? A man is such a fool for shedding tears because he isn't going to be alive a thousand years from now. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 077) | |
| A reaction: These thoughts are traditional, dating back to Epicurus, but Seneca is exceptionally going at finding new variations and examples to reinforce the basic thought. |
| 13321 | Is anything sweeter than valuing yourself more when you find you are loved? [Seneca] |
| Full Idea: Can anything be sweeter than to find that you are so dear to your wife that this makes you dearer to yourself? | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 104) | |
| A reaction: Another lovely penetrating remark from Seneca. I suppose a symptom of low self-esteem might be 'why does she love someone as worthless as me?', but that would be unusual. |
| 13292 | Selfishness does not produce happiness; to live for yourself, live for others [Seneca] |
| Full Idea: No one can lead a happy life if he thinks only of himself and turns everything to his own purposes. You should live for the other person if you wish to live for yourself. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 048) | |
| A reaction: It is important to see this as a key aspect of the ancient aspiration to virtue. The end result is not far from Christianity. It is simplistic to see the quest for virtue as a crass self-obsessed quest for self-improvement. We are social. |
| 13303 | A man is as unhappy as he has convinced himself he is [Seneca] |
| Full Idea: A man is as unhappy as he has convinced himself he is. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 078) | |
| A reaction: Seneca is a very penetrating thinker about ordinary life - an aspect of philosophy which is nowadays totally neglected by the most eminent philosophers. |
| 13302 | Life is like a play - it is the quality that matters, not the length [Seneca] |
| Full Idea: As it is with a play, so it is with life - what matters is not how long the acting lasts, but how good it is. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 077) | |
| A reaction: A very nice epigram, culminating the wonderful Letter 77 on the subject of death. A play needs to be a decent length if it is to exhibit its qualities. It would be heartbreaking if all of Shakespeare's plays were just 20-minute sketches. |
| 13301 | We are scared of death - except when we are immersed in pleasure! [Seneca] |
| Full Idea: You are scared of death - but how heedless of it you are while you are dealing with a dish of choice mushrooms! | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 077) | |
| A reaction: A beautifully simple observation, from the greatest philosopher of death. Maybe hospices should concentrate on sex, drugs and rock and roll. |
| 13323 | The whole point of pleasure-seeking is novelty, and abandoning established ways [Seneca] |
| Full Idea: The whole object of luxurious living is the delight it takes in irregular ways and in not merely departing from the correct course but going to the farthest point away from it, and in eventually even taking a stand diametrically opposed to it. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 122) | |
| A reaction: A rather conservative and puritanical remark, but worthy of contemplation even for committed hedonists. It is just a sad facts that most pleasures diminish with familiarity. Small children make delightful remarks. Imagine if they repeated them. |
| 13318 | Nature doesn't give us virtue; we must unremittingly pursue it, as a training and an art [Seneca] |
| Full Idea: Nature does not give a man virtue; the process of becoming a good man is an art. ...Virtue only comes to a character which has been thoroughly schooled and trained and brought to a pitch of perfection by unremitting practice. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 090) | |
| A reaction: This is an important gloss from a leading stoic on the slogan of 'live according to nature'. One might say that the natural life must be 'tracked' (as Philip Larkin says we track happiness). The natural life is, above all, the rational life, for stoics. |
| 13324 | Living contrary to nature is like rowing against the stream [Seneca] |
| Full Idea: For those who follow nature everything is easy and straightforward, whereas for those who fight against her life is just like rowing against the stream. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 102) | |
| A reaction: A classic statement of the well-known stoic slogan, but expressed with Seneca's characteristic elegance. There is always a slight hidden of dubious fatalism in the slogan. 'Rage, rage, against the dying of the light!' - Dylan Thomas. |
| 13305 | Character is ruined by not looking back over our pasts, since the future rests on the past [Seneca] |
| Full Idea: What really ruins our characters is the fact that none of us looks back over his life. We think a little about what we are going to do, and fail to think about what we have done, yet plans for the future depend on the past. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 083) | |
| A reaction: One always assumes that writings about the wisdom of daily life will be one mass of clichés, but Seneca proves otherwise. With a pang I realise that I may be too guilty of not thinking about the past. I've even been proud of it. |
| 13308 | It's no good winning lots of fights, if you are then conquered by your own temper [Seneca] |
| Full Idea: What's the use of overcoming opponent after opponent in the wrestling or boxing rings if you can be overcome by your temper? | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
| A reaction: He has such a nice way of presenting what might be traditional and commonplace ideas. If you see life as a battle, then you should think very carefully about who the opponents are - because they may be hiding within. |
| 13312 | Excessive curiosity is a form of intemperance [Seneca] |
| Full Idea: To want to know more than is sufficient is a form of intemperance. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
| A reaction: This comes as a bit of a surprise, given the high value that philosophers place on knowledge. I'm reminded of Auberon Waugh's criticism of the Scots as a 'wildly over-educated people'. I think the problem is what you could have been doing instead. |
| 13315 | To govern used to mean to serve, not to rule; rulers did not test their powers over those who bestowed it [Seneca] |
| Full Idea: In the Golden Age, to govern was to serve, not to rule. No one used to try out the extent of his power over those to whom he owed that power in the first place. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 090) | |
| A reaction: I spent my professional career trying to persuade people that management should be a subjection to the managed. Wake up! The second half of this idea is the interesting bit - the temptation to just 'try out' your powers gets to them all. |
| 11150 | It is the mark of an educated mind to be able to entertain an idea without accepting it [Aristotle] |
| Full Idea: It is the mark of an educated mind to be able to entertain an idea without accepting it. | |
| From: Aristotle (works [c.330 BCE]) | |
| A reaction: The epigraph on a David Chalmers website. A wonderful remark, and it should be on the wall of every beginners' philosophy class. However, while it is in the spirit of Aristotle, it appears to be a misattribution with no ancient provenance. |
| 3037 | Aristotle said the educated were superior to the uneducated as the living are to the dead [Aristotle, by Diog. Laertius] |
| Full Idea: Aristotle was asked how much educated men were superior to those uneducated; "As much," he said, "as the living are to the dead." | |
| From: report of Aristotle (works [c.330 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 05.1.11 |
| 13290 | One joy of learning is making teaching possible [Seneca] |
| Full Idea: Part of my joy in learning is that it puts me in a position to teach. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 006) | |
| A reaction: This doesn't quite distinguish between bad learning and good learning, but I take a commitment to wanting to teach what you know as an essential part of wanting to know. |
| 13322 | Both teachers and pupils should aim at one thing - the improvement of the pupil [Seneca] |
| Full Idea: A person teaching and a person learning should have the same end in view: the improvement of the latter. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 108) | |
| A reaction: [He cites a philospher called Attalus for this remark] This is worthy to be up in the hall of every educational institution in the world, and especially in the staff rooms. |
| 13298 | Suicide may be appropriate even when it is not urgent, if there are few reasons against it [Seneca] |
| Full Idea: There are many occasions on which a man should leave life not only bravely but for reasons which are not as pressing as they might be - the reasons which restrain us being not so pressing either. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 077) | |
| A reaction: This is an interesting and startling claim from the great champion of suicide, who nobly and memorably committed suicide himself. But we all dread a loved one miscalculating Seneca's dialectic, and dying when living would have been better. |
| 13319 | If we control our own death, no one has power over us [Seneca] |
| Full Idea: No one has power over us when death is in our own power. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 091) | |
| A reaction: A classic slogan for the stoic view of suicide, an idea that crops up in Shakespeare's 'Julius Caesar'. He doesn't seem to have understood that they can take away your shoelaces. |
| 13320 | Sometimes we have a duty not to commit suicide, for those we love [Seneca] |
| Full Idea: There are times when, however pressing one's reasons to the contrary, one's dying breath must be held back as it is passing one's lips, even if this is torture, simply out of consideration for one's dear ones. | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 104) | |
| A reaction: This is, of course, a highly significant counterbalance to his normal acceptance of suicide. I wish anyone who is planning suicide would heed it. They have no idea how much suffering will usually result from their action. |
| 8660 | There are potential infinities (never running out), but actual infinity is incoherent [Aristotle, by Friend] |
| Full Idea: Aristotle developed his own distinction between potential infinity (never running out) and actual infinity (there being a collection of an actual infinite number of things, such as places, times, objects). He decided that actual infinity was incoherent. | |
| From: report of Aristotle (works [c.330 BCE]) by Michèle Friend - Introducing the Philosophy of Mathematics 1.3 | |
| A reaction: Friend argues, plausibly, that this won't do, since potential infinity doesn't make much sense if there is not an actual infinity of things to supply the demand. It seems to just illustrate how boggling and uncongenial infinity was to Aristotle. |
| 12058 | Aristotle's matter can become any other kind of matter [Aristotle, by Wiggins] |
| Full Idea: Aristotle's conception of matter permits any kind of matter to become any other kind of matter. | |
| From: report of Aristotle (works [c.330 BCE]) by David Wiggins - Substance 4.11.2 | |
| A reaction: This is obviously crucial background information when we read Aristotle on matter. Our 92+ elements, and fixed fundamental particles, gives a quite different picture. Aristotle would discuss form and matter quite differently now. |
| 13311 | Does time exist on its own? Did anything precede it? Did it pre-exist the cosmos? [Seneca] |
| Full Idea: Look how many questions there are on time. Does it have an existence of its own? Does anything exist prior to time, independently of it? Did it begin with the universe, or did it exist even before then? | |
| From: Seneca the Younger (Letters from a Stoic [c.60], 088) | |
| A reaction: I'm not sure that the questions have shifted or become any clearer after two thousand years, despite Einstein and co. Note that discussions of time were not initiated by Augustine. |
| 22729 | The concepts of gods arose from observing the soul, and the cosmos [Aristotle, by Sext.Empiricus] |
| Full Idea: Aristotle said that the conception of gods arose among mankind from two originating causes, namely from events which concern the soul and from celestial phenomena. | |
| From: report of Aristotle (works [c.330 BCE], Frag 10) by Sextus Empiricus - Against the Physicists (two books) I.20 | |
| A reaction: The cosmos suggests order, and possible creation. What do events of the soul suggest? It doesn't seem to be its non-physical nature, because Aristotle is more of a functionalist. Puzzling. (It says later that gods are like the soul). |