Combining Philosophers

All the ideas for Luitzen E.J. Brouwer, H. Paul Grice and Antoine Arnauld

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25 ideas

1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
The greatest philosophers are methodical; it is what makes them great [Grice]
     Full Idea: The greatest philosophers have been the greatest, and most self-conscious, methodologists; indeed, I am tempted to regard the fact as primarily accounting for their greatness as philosophers.
     From: H. Paul Grice (Reply to Richards [1986], p.66), quoted by Stephen Boulter - Why Medieval Philosophy Matters 3
     A reaction: I agree. Philosophy is nothing if it is not devoted to the attempt to be fully rational, and that implies consistency and coherence. If a thinker doesn't even try to be systematic, I would not consider them to be a philosopher.
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
No one can conceive of a possible substance, apart from those which God has created [Arnauld]
     Full Idea: I am much mistaken if there is anyone who dares to say that he can conceive of a purely possible substance, …for although one talks so much of them, one never conceives them except according to the notion of those which God has created.
     From: Antoine Arnauld (Letters to Leibniz [1686], 1686.05.13), quoted by David Wiggins - Sameness and Substance 4.2
     A reaction: This idea cashes out in the 'necessitism' of Tim Williamson, and views on the Barcan formulae in modal logic.
4. Formal Logic / E. Nonclassical Logics / 7. Paraconsistency
Our dislike of contradiction in logic is a matter of psychology, not mathematics [Brouwer]
     Full Idea: Not to the mathematician, but to the psychologist, belongs the task of explaining why ...we are averse to so-called contradictory systems in which the negative as well as the positive of certain propositions are valid.
     From: Luitzen E.J. Brouwer (Intuitionism and Formalism [1912], p.79)
     A reaction: Was the turning point of Graham Priest's life the day he read this sentence? I don't agree. I take the principle of non-contradiction to be a highly generalised observation of how the world works (and Russell agrees with me).
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
For intuitionists excluded middle is an outdated historical convention [Brouwer]
     Full Idea: From the intuitionist standpoint the dogma of the universal validity of the principle of excluded third in mathematics can only be considered as a phenomenon of history of civilization, like the rationality of pi or rotation of the sky about the earth.
     From: Luitzen E.J. Brouwer (works [1930]), quoted by Shaughan Lavine - Understanding the Infinite VI.2
     A reaction: [Brouwer 1952:510-11]
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
Mathematics is a mental activity which does not use language [Brouwer, by Bostock]
     Full Idea: Brouwer made the rather extraordinary claim that mathematics is a mental activity which uses no language.
     From: report of Luitzen E.J. Brouwer (Mathematics, Science and Language [1928]) by David Bostock - Philosophy of Mathematics 7.1
     A reaction: Since I take language to have far less of a role in thought than is commonly believed, I don't think this idea is absurd. I would say that we don't use language much when we are talking!
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / h. Reals from Cauchy
Brouwer saw reals as potential, not actual, and produced by a rule, or a choice [Brouwer, by Shapiro]
     Full Idea: In his early writing, Brouwer took a real number to be a Cauchy sequence determined by a rule. Later he augmented rule-governed sequences with free-choice sequences, but even then the attitude is that Cauchy sequences are potential, not actual infinities.
     From: report of Luitzen E.J. Brouwer (works [1930]) by Stewart Shapiro - Philosophy of Mathematics 6.6
     A reaction: This is the 'constructivist' view of numbers, as espoused by intuitionists like Brouwer.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / g. Applying mathematics
Scientific laws largely rest on the results of counting and measuring [Brouwer]
     Full Idea: A large part of the natural laws introduced by science treat only of the mutual relations between the results of counting and measuring.
     From: Luitzen E.J. Brouwer (Intuitionism and Formalism [1912], p.77)
     A reaction: His point, I take it, is that the higher reaches of numbers have lost touch with the original point of the system. I now see the whole issue as just depending on conventions about the agreed extension of the word 'number'.
Brouwer regards the application of mathematics to the world as somehow 'wicked' [Brouwer, by Bostock]
     Full Idea: Brouwer regards as somehow 'wicked' the idea that mathematics can be applied to a non-mental subject matter, the physical world, and that it might develop in response to the needs which that application reveals.
     From: report of Luitzen E.J. Brouwer (Mathematics, Science and Language [1928]) by David Bostock - Philosophy of Mathematics 7.1
     A reaction: The idea is that mathematics only concerns creations of the human mind. It presumably has no more application than, say, noughts-and-crosses.
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / b. Intuitionism
Intuitionists only accept denumerable sets [Brouwer]
     Full Idea: The intuitionist recognises only the existence of denumerable sets.
     From: Luitzen E.J. Brouwer (Intuitionism and Formalism [1912], p.80)
     A reaction: That takes you up to omega, but not beyond, presumably because it then loses sight of the original intuition of 'bare two-oneness' (Idea 12453). I sympathise, but the word 'number' has shifted its meaning a lot these days.
Neo-intuitionism abstracts from the reuniting of moments, to intuit bare two-oneness [Brouwer]
     Full Idea: Neo-intuitionism sees the falling apart of moments, reunited while remaining separated in time, as the fundamental phenomenon of human intellect, passing by abstracting to mathematical thinking, the intuition of bare two-oneness.
     From: Luitzen E.J. Brouwer (Intuitionism and Formalism [1912], p.80)
     A reaction: [compressed] A famous and somewhat obscure idea. He goes on to say that this creates one and two, and all the finite ordinals.
Intuitionist mathematics deduces by introspective construction, and rejects unknown truths [Brouwer]
     Full Idea: Mathematics rigorously treated from the point of view of deducing theorems exclusively by means of introspective construction, is called intuitionistic mathematics. It deviates from classical mathematics, which believes in unknown truths.
     From: Luitzen E.J. Brouwer (Consciousness, Philosophy and Mathematics [1948]), quoted by Stewart Shapiro - Thinking About Mathematics 1.2
     A reaction: Clearly intuitionist mathematics is a close cousin of logical positivism and the verification principle. This view would be anathema to Frege, because it is psychological. Personally I believe in the existence of unknown truths, big time!
10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals
Conditionals are truth-functional, but we must take care with misleading ones [Grice, by Edgington]
     Full Idea: Grice argued that the truth-functional account of conditionals can withstand objections, provided that we are careful to distinguish the false from the misleadingly true.
     From: report of H. Paul Grice (Logic and Conversation [1975]) by Dorothy Edgington - Do Conditionals Have Truth Conditions? 2
The odd truth table for material conditionals is explained by conversational conventions [Grice, by Fisher]
     Full Idea: According to Grice, it is the rules that govern conversation beyond the merely logical that account for the counter-intuitiveness of the truth table for the material conditional.
     From: report of H. Paul Grice (Logic and Conversation [1975]) by Jennifer Fisher - On the Philosophy of Logic 8.I
     A reaction: There is a conversational rule which says that replies should normally relevant to context. It would be nice if logical implications were also relevant to context.
Conditionals might remain truth-functional, despite inappropriate conversational remarks [Edgington on Grice]
     Full Idea: Grice defended the truth-functional account of conditionals, noting the gap between what we are justified in believing and what is appropriate to say. .But the problem arises at the level of belief, not at the level of inappropriate conversational remarks
     From: comment on H. Paul Grice (Logic and Conversation [1975]) by Dorothy Edgington - Conditionals 17.1.3
10. Modality / B. Possibility / 8. Conditionals / f. Pragmatics of conditionals
Conditionals are truth-functional, but unassertable in tricky cases? [Grice, by Read]
     Full Idea: The 'conversational defence' of the truth-functional view of conditionals is that a conditional may not be assertible in difficult cases.
     From: report of H. Paul Grice (Presupposition and Conversational Implicature [1977]) by Stephen Read - Thinking About Logic Ch.3
A person can be justified in believing a proposition, though it is unreasonable to actually say it [Grice, by Edgington]
     Full Idea: Grice drew attention to situations in which a person is justified in believing a proposition, which would nevertheless by an unreasonable thing for the person to say, in normal circumstances. I think he is right about disjunction and negated conjunctions.
     From: report of H. Paul Grice (Logic and Conversation [1975]) by Dorothy Edgington - Conditionals (Stanf) 2.4
     A reaction: Edgington considers Grice's ideas of implicature as of permanent value, especially as a clarification of 1950s ordinary language philosophy.
19. Language / A. Nature of Meaning / 3. Meaning as Speaker's Intention
Meaning needs an intention to induce a belief, and a recognition that this is the speaker's intention [Grice]
     Full Idea: For a statement to have (non-naturally) meant something, not merely must it have been 'uttered' with the intention of inducing a certain belief, but also the utterer must have intended an 'audience' to recognise the intention behind the utterance.
     From: H. Paul Grice (Meaning [1957], p.43)
     A reaction: This is Grice's famous and distinctive theory of meaning. I am struck by the problem of a password, which seems to have a quite different intention from its literal meaning. Also a speaker with two different audiences and opposite intentions.
Only the utterer's primary intention is relevant to the meaning [Grice]
     Full Idea: Only what I may call the primary intention of an utterer is relevant to the (non-natural) meaning of an utterance.
     From: H. Paul Grice (Meaning [1957], p.47)
     A reaction: This sounds okay for simple statements, but gets really tricky with complex statements, such as very ironic remarks delivered to an audience of diverse people.
We judge linguistic intentions rather as we judge non-linguistic intentions, so they are alike [Grice]
     Full Idea: To show that the criteria for judging linguistic intentions are very like the criteria for judging non-linguistic intentions is to show that linguistic intentions are very like non-linguistic intentions.
     From: H. Paul Grice (Meaning [1957], p.48)
     A reaction: This hint at the end of his paper is one of the key attractions of Grice's view. It offers an account of language that fits it into the world of animal communication and evolution. It never seems to quite capture the way meaning goes beyond intentions.
19. Language / A. Nature of Meaning / 5. Meaning as Verification
Intuitonists in mathematics worried about unjustified assertion, as well as contradiction [Brouwer, by George/Velleman]
     Full Idea: The concern of mathematical intuitionists was that the use of certain forms of inference generates, not contradiction, but unjustified assertions.
     From: report of Luitzen E.J. Brouwer (Intuitionism and Formalism [1912]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.6
     A reaction: This seems to be the real origin of the verificationist idea in the theory of meaning. It is a hugely revolutionary idea - that ideas are not only ruled out of court by contradiction, but that there are other criteria which should also be met.
19. Language / A. Nature of Meaning / 6. Meaning as Use
Grice said patterns of use are often semantically irrelevant, because it is a pragmatic matter [Grice, by Glock]
     Full Idea: The slogan that meaning is use came under scrutiny by Grice's theory of conversational implicature. He said patterns of use shown in analysis were often semantically irrelevant, snce they are due not meanings of expressions but to pragmatic principles.
     From: report of H. Paul Grice (Some Models for Implicature [1967]) by Hans-Johann Glock - What is Analytic Philosophy? 2.8
     A reaction: I think the simplest objection is that words only have use because they have a meaning; The most interesting part of pragmatics is what you DON'T say in conversation.
19. Language / F. Communication / 5. Pragmatics / b. Implicature
Grice's maxim of quality says do not assert what you believe to be false [Grice, by Magidor]
     Full Idea: Grice's maxim of quality says one ought not to assert what one believes to be false.
     From: report of H. Paul Grice (Some Models for Implicature [1967]) by Ofra Magidor - Category Mistakes 5.2
     A reaction: The obvious exception is irony, where are truth is asserted, but the listener is supposed to spot that you are not really asserting it.
Grice's maxim of manner requires one to be as brief as possible [Grice, by Magidor]
     Full Idea: Grice's maxim of manner requires one to be as brief as possible.
     From: report of H. Paul Grice (Some Models for Implicature [1967]) by Ofra Magidor - Category Mistakes 5.2
     A reaction: An alternative maxim of conversation is that there should not be long silences between contributions - which would probably result if the contributions are all curtly abbreviated.
Key conversational maxims are 'quality' (assert truth) and 'quantity' (leave nothing out) [Grice, by Read]
     Full Idea: Grice particularly identified two maxims as guiding conversation: the maxim of 'quality' (that one should assert only what one believes to be true and justified), and of 'quantity' (one should not assert less than one can).
     From: report of H. Paul Grice (Presupposition and Conversational Implicature [1977]) by Stephen Read - Thinking About Logic Ch.3
     A reaction: I think it would be very foolish to boldly embrace the second maxim when talking to strangers. If white lies are occasionally acceptable, then what is the status of the first 'maxim'? Is it a moral maxim?
Grice's maxim of quantity says be sufficiently informative [Grice, by Magidor]
     Full Idea: Grice's maxim of quantity says 'make your contributions as informative as required'.
     From: report of H. Paul Grice (Some Models for Implicature [1967]) by Ofra Magidor - Category Mistakes 5.2
     A reaction: Is the 'requirement' of informative for the speaker or for the listener? It is easy to image situations where, one way or the other, the two people don't agree about informativenss.