80 ideas
23890 | For Plato true wisdom is supernatural [Plato, by Weil] |
Full Idea: It is evident that Plato regards true wisdom as something supernatural. | |
From: report of Plato (works [c.375 BCE]) by Simone Weil - God in Plato p.61 | |
A reaction: Taken literally, I assume this is wrong, but we can empathise with the thought. Wisdom has the feeling of rising above the level of mere knowledge, to achieve the overview I associate with philosophy. |
13860 | We can only learn from philosophers of the past if we accept the risk of major misrepresentation [Wright,C] |
Full Idea: We can learn from the work of philosophers of other periods only if we are prepared to run the risk of radical and almost inevitable misrepresentation of his thought. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Pref) | |
A reaction: This sounds about right, and a motto for my own approach to Aristotle and Leibniz, but I see the effort as more collaborative than this suggests. Professional specialists in older philosophers are a vital part of the team. Read them! |
3060 | Plato never mentions Democritus, and wished to burn his books [Plato, by Diog. Laertius] |
Full Idea: Plato, who mentions nearly all the ancient philosophers, nowhere speaks of Democritus; he wished to burn all of his books, but was persuaded that it was futile. | |
From: report of Plato (works [c.375 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.7.8 |
23891 | Two contradictories force us to find a relation which will correlate them [Plato, by Weil] |
Full Idea: Where contradictions appear there is a correlation of contraries, which is relation. If a contradiction is imposed on the intelligence, it is forced to think of a relation to transform the contradiction into a correlation, which draws the soul higher. | |
From: report of Plato (works [c.375 BCE]) by Simone Weil - God in Plato p.70 | |
A reaction: A much better account of the dialectic than anything I have yet seen in Hegel. For the first time I see some sense in it. A contradiction is not a falsehood, and it must be addressed rather than side-stepped. A kink in the system, that needs ironing. |
13883 | The best way to understand a philosophical idea is to defend it [Wright,C] |
Full Idea: The most productive way in which to attempt an understanding of any philosophical idea is to work on its defence. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.vii) | |
A reaction: Very nice. The key point is that this brings greater understanding than working on attacking an idea, which presumably has the dangers of caricature, straw men etc. It is the Socratic insight that dialectic is the route to wisdom. |
10142 | The attempt to define numbers by contextual definition has been revived [Wright,C, by Fine,K] |
Full Idea: Frege gave up on the attempt to introduce natural numbers by contextual definition, but the project has been revived by neo-logicists. | |
From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Kit Fine - The Limits of Abstraction II |
9868 | An expression refers if it is a singular term in some true sentences [Wright,C, by Dummett] |
Full Idea: For Wright, an expression refers to an object if it fulfils the 'syntactic role' of a singular term, and if we have fixed the truth-conditions of sentences containing it in such a way that some of them come out true. | |
From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Michael Dummett - Frege philosophy of mathematics Ch.15 | |
A reaction: Much waffle is written about reference, and it is nice to hear of someone actually trying to state the necessary and sufficient conditions for reference to be successful. So is it possible for 'the round square' to ever refer? '...is impossible to draw' |
20457 | Zeno assumes collecting an infinity of things makes an infinite thing [Rovelli] |
Full Idea: One possible answer is that Zeno is wrong because it is not true that by accumulating an infinite number of things one ends up with an infinite thing. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 01) | |
A reaction: I do love it when deep and complex ideas are expressed with perfect simplicity. As long as the simple version is correct. |
13861 | Number theory aims at the essence of natural numbers, giving their nature, and the epistemology [Wright,C] |
Full Idea: In the Fregean view number theory is a science, aimed at those truths furnished by the essential properties of zero and its successors. The two broad question are then the nature of the objects, and the epistemology of those facts. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Intro) | |
A reaction: [compressed] I pounce on the word 'essence' here (my thing). My first question is about the extent to which the natural numbers all have one generic essence, and the extent to which they are individuals (bless their little cotton socks). |
13892 | One could grasp numbers, and name sizes with them, without grasping ordering [Wright,C] |
Full Idea: Someone could be clear about number identities, and distinguish numbers from other things, without conceiving them as ordered in a progression at all. The point of them would be to make comparisons between sizes of groups. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 3.xv) | |
A reaction: Hm. Could you grasp size if you couldn't grasp which of two groups was the bigger? What's the point of noting that I have ten pounds and you only have five, if you don't realise that I have more than you? You could have called them Caesar and Brutus. |
13867 | Instances of a non-sortal concept can only be counted relative to a sortal concept [Wright,C] |
Full Idea: The invitation to number the instances of some non-sortal concept is intelligible only if it is relativised to a sortal. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i) | |
A reaction: I take this to be an essentially Fregean idea, as when we count the boots when we have decided whether they fall under the concept 'boot' or the concept 'pair'. I also take this to be the traditional question 'what units are you using'? |
13862 | There are five Peano axioms, which can be expressed informally [Wright,C] |
Full Idea: Informally, Peano's axioms are: 0 is a number, numbers have a successor, different numbers have different successors, 0 isn't a successor, properties of 0 which carry over to successors are properties of all numbers. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Intro) | |
A reaction: Each statement of the famous axioms is slightly different from the others, and I have reworded Wright to fit him in. Since the last one (the 'induction axiom') is about properties, it invites formalization in second-order logic. |
17853 | Number truths are said to be the consequence of PA - but it needs semantic consequence [Wright,C] |
Full Idea: The intuitive proposal is the essential number theoretic truths are precisely the logical consequences of the Peano axioms, ...but the notion of consequence is a semantic one...and it is not obvious that we possess a semantic notion of the requisite kind. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Intro) | |
A reaction: (Not sure I understand this, but it is his starting point for rejecting PA as the essence of arithmetic). |
17854 | What facts underpin the truths of the Peano axioms? [Wright,C] |
Full Idea: We incline to think of the Peano axioms as truths of some sort; so there has to be a philosophical question how we ought to conceive of the nature of the facts which make those statements true. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Intro) | |
A reaction: [He also asks about how we know the truths] |
17441 | Wright thinks Hume's Principle is more fundamental to cardinals than the Peano Axioms are [Wright,C, by Heck] |
Full Idea: Wright is claiming that HP is a special sort of truth in some way: it is supposed to be the fundamental truth about cardinality; ...in particular, HP is supposed to be more fundamental, in some sense than the Dedekind-Peano axioms. | |
From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Richard G. Heck - Cardinality, Counting and Equinumerosity 1 | |
A reaction: Heck notes that although PA can be proved from HP, HP can be proven from PA plus definitions, so direction of proof won't show fundamentality. He adds that Wright thinks HP is 'more illuminating'. |
13894 | Sameness of number is fundamental, not counting, despite children learning that first [Wright,C] |
Full Idea: We teach our children to count, sometimes with no attempt to explain what the sounds mean. Doubtless it is this habit which makes it so natural to think of the number series as fundamental. Frege's insight is that sameness of number is fundamental. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 3.xv) | |
A reaction: 'When do children understand number?' rather than when they can recite numerals. I can't make sense of someone being supposed to understand number without a grasp of which numbers are bigger or smaller. To make 13='15' do I add or subtract? |
10140 | We derive Hume's Law from Law V, then discard the latter in deriving arithmetic [Wright,C, by Fine,K] |
Full Idea: Wright says the Fregean arithmetic can be broken down into two steps: first, Hume's Law may be derived from Law V; and then, arithmetic may be derived from Hume's Law without any help from Law V. | |
From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Kit Fine - The Limits of Abstraction I.4 | |
A reaction: This sounds odd if Law V is false, but presumably Hume's Law ends up as free-standing. It seems doubtful whether the resulting theory would count as logic. |
8692 | Frege has a good system if his 'number principle' replaces his basic law V [Wright,C, by Friend] |
Full Idea: Wright proposed removing Frege's basic law V (which led to paradox), replacing it with Frege's 'number principle' (identity of numbers is one-to-one correspondence). The new system is formally consistent, and the Peano axioms can be derived from it. | |
From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Michčle Friend - Introducing the Philosophy of Mathematics 3.7 | |
A reaction: The 'number principle' is also called 'Hume's principle'. This idea of Wright's resurrected the project of logicism. The jury is ought again... Frege himself questioned whether the number principle was a part of logic, which would be bad for 'logicism'. |
17440 | Wright says Hume's Principle is analytic of cardinal numbers, like a definition [Wright,C, by Heck] |
Full Idea: Wright intends the claim that Hume's Principle (HP) embodies an explanation of the concept of number to imply that it is analytic of the concept of cardinal number - so it is an analytic or conceptual truth, much as a definition would be. | |
From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Richard G. Heck - Cardinality, Counting and Equinumerosity 1 | |
A reaction: Boolos is quoted as disagreeing. Wright is claiming a fundamental truth. Boolos says something can fix the character of something (as yellow fixes bananas), but that doesn't make it 'fundamental'. I want to defend 'fundamental'. |
13893 | It is 1-1 correlation of concepts, and not progression, which distinguishes natural number [Wright,C] |
Full Idea: What is fundamental to possession of any notion of natural number at all is not the knowledge that the numbers may be arrayed in a progression but the knowledge that they are identified and distinguished by reference to 1-1 correlation among concepts. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 3.xv) | |
A reaction: My question is 'what is the essence of number?', and my inclination to disagree with Wright on this point suggests that the essence of number is indeed caught in the Dedekind-Peano axioms. But what of infinite numbers? |
13888 | If numbers are extensions, Frege must first solve the Caesar problem for extensions [Wright,C] |
Full Idea: Identifying numbers with extensions will not solve the Caesar problem for numbers unless we have already solved the Caesar problem for extensions. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 3.xiv) |
13869 | Number platonism says that natural number is a sortal concept [Wright,C] |
Full Idea: Number-theoretic platonism is just the thesis that natural number is a sortal concept. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i) | |
A reaction: See Crispin Wright on sortals to expound this. An odd way to express platonism, but he is presenting the Fregean version of it. |
13870 | We can't use empiricism to dismiss numbers, if numbers are our main evidence against empiricism [Wright,C] |
Full Idea: We may not be able to settle whether some general form of empiricism is correct independently of natural numbers. It might be precisely our grasp of the abstract sortal, natural number, which shows the hypothesis of empiricism to be wrong. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i) | |
A reaction: A nice turning of the tables. In the end only coherence decides these things. You may accept numbers and reject empiricism, and then find you have opened the floodgates for abstracta. Excessive floodgates, or blockages of healthy streams? |
13873 | Treating numbers adjectivally is treating them as quantifiers [Wright,C] |
Full Idea: Treating numbers adjectivally is, in effect, treating the numbers as quantifiers. Frege observes that we can always parse out any apparently adjectival use of a number word in terms of substantival use. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.iii) | |
A reaction: The immediate response to this is that any substantival use can equally be expressed adjectivally. If you say 'the number of moons of Jupiter is four', I can reply 'oh, you mean Jupiter has four moons'. |
13899 | The Peano Axioms, and infinity of cardinal numbers, are logical consequences of how we explain cardinals [Wright,C] |
Full Idea: The Peano Axioms are logical consequences of a statement constituting the core of an explanation of the notion of cardinal number. The infinity of cardinal numbers emerges as a consequence of the way cardinal number is explained. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 4.xix) | |
A reaction: This, along with Idea 13896, nicely summarises the neo-logicist project. I tend to favour a strategy which starts from ordering, rather than identities (1-1), but an attraction is that this approach is closer to counting objects in its basics. |
13896 | The aim is to follow Frege's strategy to derive the Peano Axioms, but without invoking classes [Wright,C] |
Full Idea: We shall endeavour to see whether it is possible to follow through the strategy adumbrated in 'Grundlagen' for establishing the Peano Axioms without at any stage invoking classes. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 4.xvi) | |
A reaction: The key idea of neo-logicism. If you can avoid classes entirely, then set theory paradoxes become irrelevant, and classes aren't logic. Philosophers now try to derive the Peano Axioms from all sorts of things. Wright admits infinity is a problem. |
7804 | Wright has revived Frege's discredited logicism [Wright,C, by Benardete,JA] |
Full Idea: Crispin Wright has reactivated Frege's logistic program, which for decades just about everybody assumed was a lost cause. | |
From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by José A. Benardete - Logic and Ontology 3 | |
A reaction: [This opens Bernadete's section called "Back to Strong Logicism?"] |
13863 | Logicism seemed to fail by Russell's paradox, Gödel's theorems, and non-logical axioms [Wright,C] |
Full Idea: Most would cite Russell's paradox, the non-logical character of the axioms which Russell and Whitehead's reconstruction of Frege's enterprise was constrained to employ, and the incompleteness theorems of Gödel, as decisive for logicism's failure. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], Intro) |
13895 | The standard objections are Russell's Paradox, non-logical axioms, and Gödel's theorems [Wright,C] |
Full Idea: The general view is that Russell's Paradox put paid to Frege's logicist attempt, and Russell's own attempt is vitiated by the non-logical character of his axioms (esp. Infinity), and by the incompleteness theorems of Gödel. But these are bad reasons. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 4.xvi) | |
A reaction: Wright's work is the famous modern attempt to reestablish logicism, in the face of these objections. |
13884 | The idea that 'exist' has multiple senses is not coherent [Wright,C] |
Full Idea: I have the gravest doubts whether any coherent account could be given of any multiplicity of senses of 'exist'. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 2.x) | |
A reaction: I thoroughly agree with this thought. Do water and wind exist in different senses of 'exist'? |
20468 | Quantum mechanics deals with processes, rather than with things [Rovelli] |
Full Idea: Quantum mechanics teaches us not to think about the world in terms of 'things' which are in this or that state, but in terms of 'processes' instead. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) |
20467 | Quantum mechanics describes the world entirely as events [Rovelli] |
Full Idea: The world of quantum mechanics is not a world of objects: it is a world of events. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: I presume a philosopher is allowed to ask what an 'event' is. Since, as Rovelli tells it, time is eliminated from the picture, events seem to be unanalysable primitives. |
13877 | Singular terms in true sentences must refer to objects; there is no further question about their existence [Wright,C] |
Full Idea: When a class of terms functions as singular terms, and the sentences are true, then those terms genuinely refer. Being singular terms, their reference is to objects. There is no further question whether they really refer, and there are such objects. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.iii) | |
A reaction: This seems to be a key sentence, because this whole view is standardly called 'platonic', but it certainly isn't platonism as we know it, Jim. Ontology has become an entirely linguistic matter, but do we then have 'sakes' and 'whereaboutses'? |
14502 | Plato's idea of 'structure' tends to be mathematically expressed [Plato, by Koslicki] |
Full Idea: 'Structure' tends to be characterized by Plato as something that is mathematically expressed. | |
From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects V.3 iv | |
A reaction: [Koslicki is drawing on Verity Harte here] |
17948 | Plato's Forms meant that the sophists only taught the appearance of wisdom and virtue [Plato, by Nehamas] |
Full Idea: Plato's theory of Forms allowed him to claim that the sophists and other opponents were trapped in the world of appearance. What they therefore taught was only apparent wisdom and virtue. | |
From: report of Plato (works [c.375 BCE]) by Alexander Nehamas - Eristic,Antilogic,Sophistic,Dialectic p.118 |
20906 | Platonists argue for the indivisible triangle-in-itself [Plato, by Aristotle] |
Full Idea: The Platonists, on the basis of purely logical arguments, posit the existence of an indivisible 'triangle in itself'. | |
From: report of Plato (works [c.375 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 316a15 | |
A reaction: A helpful confirmation that geometrical figures really are among the Forms (bearing in mind that numbers are not, because they contain one another). What shape is the Form of the triangle? |
3039 | When Diogenes said he could only see objects but not their forms, Plato said it was because he had eyes but no intellect [Plato, by Diog. Laertius] |
Full Idea: When Diogenes told Plato he saw tables and cups, but not 'tableness' and 'cupness', Plato replied that this was because Diogenes had eyes but no intellect. | |
From: report of Plato (works [c.375 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 06.2.6 |
556 | If there is one Form for both the Form and its participants, they must have something in common [Aristotle on Plato] |
Full Idea: If there is the same Form for the Forms and for their participants, then they must have something in common. | |
From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 991a |
563 | If gods are like men, they are just eternal men; similarly, Forms must differ from particulars [Aristotle on Plato] |
Full Idea: We say there is the form of man, horse and health, but nothing else, making the same mistake as those who say that there are gods but that they are in the form of men. They just posit eternal men, and here we are not positing forms but eternal sensibles. | |
From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 997b |
557 | A Form is a cause of things only in the way that white mixed with white is a cause [Aristotle on Plato] |
Full Idea: A Form is a cause of things only in the way that white mixed with white is a cause. | |
From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 991a |
565 | The Forms cannot be changeless if they are in changing things [Aristotle on Plato] |
Full Idea: The Forms could not be changeless if they were in changing things. | |
From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 998a |
9607 | The greatest discovery in human thought is Plato's discovery of abstract objects [Brown,JR on Plato] |
Full Idea: The greatest discovery in the history of human thought is Plato's discovery of abstract objects. | |
From: comment on Plato (works [c.375 BCE]) by James Robert Brown - Philosophy of Mathematics Ch. 2 | |
A reaction: Compare Idea 2860! Given the diametrically opposed views, it is clearly likely that Plato's central view is the most important idea in the history of human thought, even if it is wrong. |
9878 | Contextually defined abstract terms genuinely refer to objects [Wright,C, by Dummett] |
Full Idea: Wright says we should accord to contextually defined abstract terms a genuine full-blown reference to objects. | |
From: report of Crispin Wright (Frege's Concept of Numbers as Objects [1983]) by Michael Dummett - Frege philosophy of mathematics Ch.18 | |
A reaction: This is the punch line of Wright's neo-logicist programme. See Idea 9868 for his view of reference. Dummett regards this strong view of contextual definition as 'exorbitant'. Wright's view strikes me as blatantly false. |
13263 | We can grasp whole things in science, because they have a mathematics and a teleology [Plato, by Koslicki] |
Full Idea: Due to the mathematical nature of structure and the teleological cause underlying the creation of Platonic wholes, these wholes are intelligible, and are in fact the proper objects of science. | |
From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.3 | |
A reaction: I like this idea, because it pays attention to the connection between how we conceive objects to be, and how we are able to think about objects. Only examining these two together enables us to grasp metaphysics. |
13868 | Sortal concepts cannot require that things don't survive their loss, because of phase sortals [Wright,C] |
Full Idea: The claim that no concept counts as sortal if an instance of it can survive its loss, runs foul of so-called phase sortals like 'embryo' and 'chrysalis'. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i) | |
A reaction: The point being that those items only fall under that sortal for one phase of their career, and of their identity. I've always thought such claims absurd, and this gives a good reason for my view. |
13261 | Plato sees an object's structure as expressible in mathematics [Plato, by Koslicki] |
Full Idea: The 'structure' of an object tends to be characterised by Plato as something that is mathematically expressible. | |
From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.3 | |
A reaction: This seems to be pure Pythagoreanism (see Idea 644). Plato is pursuing Pythagoras's research programme, of trying to find mathematics buried in every aspect of reality. |
13265 | Plato was less concerned than Aristotle with the source of unity in a complex object [Plato, by Koslicki] |
Full Idea: Plato was less concerned than Aristotle with the project of how to account, in completely general terms, for the source of unity within a mereologically complex object. | |
From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.5 | |
A reaction: Plato seems to have simply asserted that some sort of harmony held things together. Aristotles puts the forms [eidos] within objects, rather than external, so he has to give a fuller account of what is going on in an object. He never managed it! |
593 | Plato's holds that there are three substances: Forms, mathematical entities, and perceptible bodies [Plato, by Aristotle] |
Full Idea: Plato's doctrine was that the Forms and mathematicals are two substances and that the third substance is that of perceptible bodies. | |
From: report of Plato (works [c.375 BCE]) by Aristotle - Metaphysics 1028b |
13260 | Plato says wholes are either containers, or they're atomic, or they don't exist [Plato, by Koslicki] |
Full Idea: Plato considers a 'container' model for wholes (which are disjoint from their parts) [Parm 144e3-], and a 'nihilist' model, in which only wholes are mereological atoms, and a 'bare pluralities' view, in which wholes are not really one at all. | |
From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.2 | |
A reaction: [She cites Verity Harte for this analysis of Plato] The fourth, and best, seems to be that wholes are parts which fall under some unifying force or structure or principle. |
11237 | Only universals have essence [Plato, by Politis] |
Full Idea: Plato argues that only universals have essence. | |
From: report of Plato (works [c.375 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 1.4 |
11238 | Plato and Aristotle take essence to make a thing what it is [Plato, by Politis] |
Full Idea: Plato and Aristotle have a shared general conception of essence: the essence of a thing is what that thing is simply in virtue of itself and in virtue of being the very thing it is. It answers the question 'What is this very thing?' | |
From: report of Plato (works [c.375 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 1.4 |
17085 | A good explanation totally rules out the opposite explanation (so Forms are required) [Plato, by Ruben] |
Full Idea: For Plato, an acceptable explanation is one such that there is no possibility of there being the opposite explanation at all, and he thought that only explanations in terms of the Forms, but never physical explanations, could meet this requirement. | |
From: report of Plato (works [c.375 BCE]) by David-Hillel Ruben - Explaining Explanation Ch 2 | |
A reaction: [Republic 436c is cited] |
1651 | Plato wanted to somehow control and purify the passions [Vlastos on Plato] |
Full Idea: Plato put high on his agenda a project which did not figure in Socrates' programme at all: the hygienic conditioning of the passions. This cannot be an intellectual process, as argument cannot touch them. | |
From: comment on Plato (works [c.375 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.88 | |
A reaction: This is the standard traditional view of any thinker who exaggerates the importance and potential of reason in our lives. |
13866 | A concept is only a sortal if it gives genuine identity [Wright,C] |
Full Idea: Before we can conclude that φ expresses a sortal concept, we need to ensure that 'is the same φ as' generates statements of genuine identity rather than of some other equivalence relation. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i) |
13865 | 'Sortal' concepts show kinds, use indefinite articles, and require grasping identities [Wright,C] |
Full Idea: A concept is 'sortal' if it exemplifies a kind of object. ..In English predication of a sortal concept needs an indefinite article ('an' elm). ..What really constitutes the distinction is that it involves grasping identity for things which fall under it. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.i) | |
A reaction: This is a key notion, which underlies the claims of 'sortal essentialism' (see David Wiggins). |
13890 | Entities fall under a sortal concept if they can be used to explain identity statements concerning them [Wright,C] |
Full Idea: 'Tree' is not a sortal concept under which directions fall since we cannot adequately explain the truth-conditions of any identity statement involving a pair of tree-denoting singular terms by appealing to facts to do with parallelism between lines. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 3.xiv) | |
A reaction: The idea seems to be that these two fall under 'hedgehog', because that is a respect in which they are identical. I like to notion of explanation as a part of this. |
13898 | If we can establish directions from lines and parallelism, we were already committed to directions [Wright,C] |
Full Idea: The fact that it seems possible to establish a sortal notion of direction by reference to lines and parallelism, discloses tacit commitments to directions in statements about parallelism...There is incoherence in the idea that a line might lack direction. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 4.xviii) | |
A reaction: This seems like a slippery slope into a very extravagant platonism about concepts. Are concepts like direction as much a part of the natural world as rivers are? What other undiscovered concepts await us? |
13882 | A milder claim is that understanding requires some evidence of that understanding [Wright,C] |
Full Idea: A mild version of the verification principle would say that it makes sense to think of someone as understanding an expression only if he is able, by his use of the expression, to give the best possible evidence that he understands it. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.vii) | |
A reaction: That doesn't seem to tell us what understanding actually consists of, and may just be the truism that to demonstrate anything whatsoever will necessarily involve some evidence. |
13885 | If apparent reference can mislead, then so can apparent lack of reference [Wright,C] |
Full Idea: If the appearance of reference can be misleading, why cannot an apparent lack of reference be misleading? | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 2.xi) | |
A reaction: A nice simple thought. Analytic philosophy has concerned itself a lot with sentences that seem to refer, but the reference can be analysed away. For me, this takes the question of reference out of the linguistic sphere, which wasn't Wright's plan. |
17857 | We can accept Frege's idea of object without assuming that predicates have a reference [Wright,C] |
Full Idea: The heart of the problem is Frege's assumption that predicates have Bedeutungen at all; and no reason is at present evident why someone who espouses Frege's notion of object is contrained to make that assumption. | |
From: Crispin Wright (Frege's Concept of Numbers as Objects [1983], 1.iv) | |
A reaction: This seems like a penetrating objection to Frege's view of reference, and presumably supports the Kripke approach. |
3324 | Plato's whole philosophy may be based on being duped by reification - a figure of speech [Benardete,JA on Plato] |
Full Idea: Plato is liable to the charge of having been duped by a figure of speech, albeit the most profound of all, the trope of reification. | |
From: comment on Plato (works [c.375 BCE]) by José A. Benardete - Metaphysics: the logical approach Ch.12 | |
A reaction: That might be a plausible account if his view was ridiculous, but given how many powerful friends Plato has, especially in the philosophy of mathematics, we should assume he was cleverer than that. |
7503 | Plato never refers to examining the conscience [Plato, by Foucault] |
Full Idea: Plato never speaks of the examination of conscience - never! | |
From: report of Plato (works [c.375 BCE]) by Michel Foucault - On the Genealogy of Ethics p.276 | |
A reaction: Plato does imply some sort of self-evident direct knowledge about that nature of a healthy soul. Presumably the full-blown concept of conscience is something given from outside, from God. In 'Euthyphro', Plato asserts the primacy of morality (Idea 337). |
2173 | As religion and convention collapsed, Plato sought morals not just in knowledge, but in the soul [Williams,B on Plato] |
Full Idea: Once gods and fate and social expectation were no longer there, Plato felt it necessary to discover ethics inside human nature, not just as ethical knowledge (Socrates' view), but in the structure of the soul. | |
From: comment on Plato (works [c.375 BCE]) by Bernard Williams - Shame and Necessity II - p.43 | |
A reaction: anti Charles Taylor |
9274 | Plato's legacy to European thought was the Good, the Beautiful and the True [Plato, by Gray] |
Full Idea: Plato's legacy to European thought was a trio of capital letters - the Good, the Beautiful and the True. | |
From: report of Plato (works [c.375 BCE]) by John Gray - Straw Dogs 2.8 | |
A reaction: It seems to have been Baumgarten who turned this into a slogan (Idea 8117). Gray says these ideals are lethal, but I identify with them very strongly, and am quite happy to see the good life as an attempt to find the right balance between them. |
94 | Pleasure is better with the addition of intelligence, so pleasure is not the good [Plato, by Aristotle] |
Full Idea: Plato says the life of pleasure is more desirable with the addition of intelligence, and if the combination is better, pleasure is not the good. | |
From: report of Plato (works [c.375 BCE]) by Aristotle - Nicomachean Ethics 1172b27 | |
A reaction: It is obvious why we like pleasure, but not why intelligence makes it 'better'. Maybe it is just because we enjoy intelligence? |
17947 | Plato decided that the virtuous and happy life was the philosophical life [Plato, by Nehamas] |
Full Idea: Plato came to the conclusion that virtue and happiness consist in the life of philosophy itself. | |
From: report of Plato (works [c.375 BCE]) by Alexander Nehamas - Eristic,Antilogic,Sophistic,Dialectic p.117 | |
A reaction: This view is obviously ridiculous, because it largely excludes almost the entire human race, which sees philosophy as a cul-de-sac, even if it is good. But virtue and happiness need some serious thought. |
6015 | Plato, unusually, said that theoretical and practical wisdom are inseparable [Plato, by Kraut] |
Full Idea: Two virtues that are ordinarily kept distinct - theoretical and practical wisdom - are joined by Plato; he thinks that neither one can be fully possessed unless it is combined with the other. | |
From: report of Plato (works [c.375 BCE]) by Richard Kraut - Plato | |
A reaction: I get the impression that this doctrine comes from Socrates, whose position is widely reported as 'intellectualist'. Aristotle certainly held the opposite view. |
2912 | Plato is boring [Nietzsche on Plato] |
Full Idea: Plato is boring. | |
From: comment on Plato (works [c.375 BCE]) by Friedrich Nietzsche - Twilight of the Idols 9.2 |
20469 | There are probably no infinities, and 'infinite' names what we do not yet know [Rovelli] |
Full Idea: 'Infinite', ultimately, is the name that we give to what we do not yet know. Nature appears to be telling us that there is nothing truly infinite. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 11) |
20461 | The basic ideas of fields and particles are merged in quantum mechanics [Rovelli] |
Full Idea: The notions of fields and particles, separated by Faraday and Maxwell, end up merging in quantum mechanics. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: This sounds to me just like Anaximander's 'apeiron' - the unlimited [Rovelli agrees! p.168]. Anaximander predicted the wall which enquiry would hit, but we now have more detail. |
20462 | Because it is quantised, a field behaves like a set of packets of energy [Rovelli] |
Full Idea: Since the energy of the electromagnetic field can take on only certain values, the field behaves like a set of packets of energy. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) |
20463 | There are about fifteen particles fields, plus a few force fields [Rovelli] |
Full Idea: There are about fifteen fields, whose quanta are elementary particles (electrons, quarks, muons, neutrinos, Higgs, and little else), plus a few fields similar to the electromagnetic one, which describe forces at a nuclear scale, with quanta like photons. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: According to Rovelli, this sentence describes the essence of physical reality. |
20464 | The world consists of quantum fields, with elementary events happening in spacetime [Rovelli] |
Full Idea: The world is not made up of fields and particles, but of a single type of entity: the quantum field. There are no longer particles which move in space with the passage of time, but quantum fields whose elementary events happen in spacetime. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: If you are not a scientist, there is (I find) a strong tendency to read and digest stuff like this, and then forget it the next day, because it so far from our experience. Folk like me have to develop two parallel views of the nature of reality. |
20459 | Electrons only exist when they interact, and their being is their combination of quantum leaps [Rovelli] |
Full Idea: Electrons don't always exist. They exist when they interact. They materialize when they collide with something. The quantum leap from one orbit to another constitutes their way of being real. An electron is a combination of leaps between interactions. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: If a philosopher with an Aristotelian interest in the nature of matter wants to grasp the modern view, the electron looks like the thing to focus on. You can feel Rovelli battling here to find formulations that might satisfy a philosopher. |
20460 | Electrons are not waves, because their collisions are at a point, and not spread out [Rovelli] |
Full Idea: Schrödinger's wave is a bad image for an electron, because when a particle collides with something else, it is always at a point: it is never spread out in space like a wave. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04 note) | |
A reaction: And yet there is the diffusion in the two-slit experiment, which Thomas Young discovered for light. I must take Rovelli's word for this. |
20466 | Quantum Theory describes events and possible interactions - not how things are [Rovelli] |
Full Idea: Quantum Theory does not describe things as they are: it describes how things occur and interact with each other. It doesn't describe where there is a particle but how it shows itself to others. The world of existence is reduced to possible interactions. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) | |
A reaction: Fans of 'process philosophy' should like this, though he is not denying that there may be facts about how things are - it is just that this is not mentioned in the theory. There is not much point in philosophers yearning to know the reality. |
20465 | Nature has three aspects: granularity, indeterminacy, and relations [Rovelli] |
Full Idea: I think that quantum mechanics has revealed three aspects of the nature of things: granularity, indeterminacy, and the relational structure of the world. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 04) |
20458 | The world is just particles plus fields; space is the gravitational field [Rovelli] |
Full Idea: The world is made up of particles + fields, and nothing else; there is no need to add space as an extra ingredient. Newton's space is the gravitational field. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 03) | |
A reaction: I get the impression that particles are just bumps or waves in the fields [yes! Rovelli p.110], which would mean there are fields and nothing else. And no one seems to know what a field is. |
20470 | Only heat distinguishes past from future [Rovelli] |
Full Idea: It is always heat and only heat that distinguishes the past from the future. | |
From: Carlo Rovelli (Reality is Not What it Seems [2014], 12) | |
A reaction: I can remember the past but not the future - so can that fact be reduced to facts about heat? |
1526 | Almost everyone except Plato thinks that time could not have been generated [Plato, by Aristotle] |
Full Idea: With a single exception (Plato) everyone agrees about time - that it is not generated. Democritus says time is an obvious example of something not generated. | |
From: report of Plato (works [c.375 BCE]) by Aristotle - Physics 251b14 |