40 ideas
| 19066 | Philosophy aims to understand the world, through ordinary experience and science [Dummett] |
| Full Idea: Philosophy is an attempt to understand the world, as it is revealed to us both in our ordinary experience and by the discoveries and theories of science. | |
| From: Michael Dummett (The Justification of Deduction [1973], p.311) | |
| A reaction: I don't see a sharp division between 'ordinary' and 'scientific'. I really like this idea, first because it makes 'understanding' central, and second because it wants both revelations. In discussing matter and time, there is too much emphasis on science. |
| 2557 | Analytical philosophy seems to have little interest in how to tell a good analysis from a bad one [Rorty] |
| Full Idea: There is nowadays little attempt to bring "analytic philosophy" to self-consciousness by explaining how to tell a successful from an unsuccessful analysis. | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], 4.1) |
| 6675 | The heart has its reasons of which reason knows nothing [Pascal] |
| Full Idea: The heart has its reasons of which reason knows nothing. | |
| From: Blaise Pascal (Pensées [1662], 423 (277)) | |
| A reaction: This romantic remark has passed into folklore. I am essentially against it, but the role of intuition and instinct are undeniable in both reasoning and ethics. I don't feel inclined, though, to let my heart overrule my reason concerning what exists. |
| 2556 | Rational certainty may be victory in argument rather than knowledge of facts [Rorty] |
| Full Idea: We can think of "rational certainty" as a matter of victory in argument rather than relation to an object known. | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], 3.4) |
| 19067 | A successful proof requires recognition of truth at every step [Dummett] |
| Full Idea: For a demonstration to be cogent it is necessary that the passage from step to step involve a recognition of truth at each line. | |
| From: Michael Dummett (The Justification of Deduction [1973], p.313) | |
| A reaction: Dummett cited Quine (esp. 1970) as having an almost entirely syntactic view of logic. Rumfitt points out that logic can move validly from one falsehood to another. Even a 'proof' might detour into falsehood, but it would not be a 'canonical' proof! |
| 4726 | Rorty seems to view truth as simply being able to hold one's view against all comers [Rorty, by O'Grady] |
| Full Idea: Rorty seems to view truth as simply being able to hold one's view against all comers. | |
| From: report of Richard Rorty (Philosophy and the Mirror of Nature [1980]) by Paul O'Grady - Relativism Ch.4 | |
| A reaction: This may be a caricature of Rorty, but he certainly seems to be in the business of denying truth as much as possible. This strikes me as the essence of pragmatism, and as a kind of philosophical nihilism. |
| 2549 | For James truth is "what it is better for us to believe" rather than a correct picture of reality [Rorty] |
| Full Idea: Truth is, in James' phrase, "what it is better for us to believe", rather than "the accurate representation of reality". | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], Intro) |
| 19060 | Truth-tables are dubious in some cases, and may be a bad way to explain connective meaning [Dummett] |
| Full Idea: It is arguable whether two-valued truth tables give correct meanings for certain sentential operators, and even whether they constitute legitimate explanations of any possible sentential operators. | |
| From: Michael Dummett (The Justification of Deduction [1973], p.294) | |
| A reaction: See 'Many-valued logic' for examples of non-binary truth tables. Presumably logicians should aspire to make their semantics precise, as well as their syntax. |
| 11066 | Deduction is justified by the semantics of its metalanguage [Dummett, by Hanna] |
| Full Idea: For Dummett the semantics of the metalanguage is the external and objective source of the justification of deduction. | |
| From: report of Michael Dummett (The Justification of Deduction [1973]) by Robert Hanna - Rationality and Logic 3.4 | |
| A reaction: This is offered as an answer to the Lewis Carroll problem that justifying deduction seems to need deduction, thus leading to a regress. [There is a reply to Dummett by Susan Haack] |
| 19058 | Syntactic consequence is positive, for validity; semantic version is negative, with counterexamples [Dummett] |
| Full Idea: A plausible account is that the syntactic notion of consequence is for positive results, that some form of argument is valid; the semantic notion is required for negative results, that some argument is invalid, because a counterexample can be found. | |
| From: Michael Dummett (The Justification of Deduction [1973], p.292) | |
| A reaction: This rings true for the two strategies of demonstration, the first by following the rules in steps, the second by using your imagination (or a tableau) to think up problems. |
| 19063 | Beth trees show semantics for intuitionistic logic, in terms of how truth has been established [Dummett] |
| Full Idea: Beth trees give a semantics for intuitionistic logic, by representing sentence meaning in terms of conditions under which it is recognised to have been established as true. | |
| From: Michael Dummett (The Justification of Deduction [1973], p.305) |
| 19059 | In standard views you could replace 'true' and 'false' with mere 0 and 1 [Dummett] |
| Full Idea: Nothing is lost, on this view, if in the standard semantic treatment of classical sentential logic, we replace the standard truth-values 'true' and 'false' by the numbers 0 and 1. | |
| From: Michael Dummett (The Justification of Deduction [1973], p.294) | |
| A reaction: [A long context will explain 'on this view'] He is discussing the relationship of syntactic and semantic consequence, and goes on to criticise simple binary truth-table accounts of connectives. Semantics on a computer would just be 0 and 1. |
| 19062 | Classical two-valued semantics implies that meaning is grasped through truth-conditions [Dummett] |
| Full Idea: The standard two-valued semantics for classical logic involves a conception under which to grasp the meaning of a sentence is to apprehend the conditions under which it is, or is not, true. | |
| From: Michael Dummett (The Justification of Deduction [1973], p.305) | |
| A reaction: The idea is that you only have to grasp the truth tables for sentential logic, and that needs nothing more than knowing whether a sentence is true or false. I'm not sure where the 'conditions' creep in, though. |
| 19065 | Soundness and completeness proofs test the theory of meaning, rather than the logic theory [Dummett] |
| Full Idea: A proof of soundess or completeness is a test, not so much of the logical theory to which it applies, but of the theory of meaning which underlies the semantics. | |
| From: Michael Dummett (The Justification of Deduction [1973], p.310) | |
| A reaction: These two types of proof concern how the syntax and the semantics match up, so this claim sounds plausible, though I tend to think of them as more like roadworthiness tests for logic, checking how well they function. |
| 22011 | The first principles of truth are not rational, but are known by the heart [Pascal] |
| Full Idea: We know the truth not only through our reason but also through our heart. It is through that latter that we know first principles, and reason, which has nothing to do with it, tries in vain to refute them. | |
| From: Blaise Pascal (Pensées [1662], 110 p.58), quoted by Terry Pinkard - German Philosophy 1760-1860 04 n4 | |
| A reaction: This resembles the rationalist defence of fundamental a priori principles, needed as a foundation for knowledge. But the a priori insights are not a feature of the 'natural light' of reason, and are presumably inexplicable (of the 'heart'). |
| 2548 | If knowledge is merely justified belief, justification is social [Rorty] |
| Full Idea: If we have a Deweyan conception of knowledge, as what we are justified in believing, we will see "justification" as a social phenomenon. | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], Intro) | |
| A reaction: I find this observation highly illuminating (though I probably need to study Dewey to understand it). There just is no absolute about whether someone is justified. How justified do you want to be? |
| 6599 | Knowing has no definable essence, but is a social right, found in the context of conversations [Rorty] |
| Full Idea: If we see knowing not as having an essence, described by scientists or philosophers, but rather as a right, by current standards, to believe, then we see conversation as the ultimate context within which knowledge is to be understood. | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], Ch.5), quoted by Robert Fogelin - Walking the Tightrope of Reason Ch.5 | |
| A reaction: This teeters towards ridiculous relativism (e.g. what if the conversation is among a group of fools? - Ah, there are no fools! Politically incorrect!). However, knowledge can be social, provided we are healthily elitist. Scientists know more than us. |
| 2566 | You can't debate about whether to have higher standards for the application of words [Rorty] |
| Full Idea: The decision about whether to have higher than usual standards for the application of words like "true" or "good" or "red" is, as far as I can see, not a debatable issue. | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], 6.6) |
| 19061 | An explanation is often a deduction, but that may well beg the question [Dummett] |
| Full Idea: An explanation is often a deductive argument, with the fact needing explaining as its conclusion. ...But the conclusion is usually given in advance, and we may only believe the premisses because they plausibly explain the conclusion. | |
| From: Michael Dummett (The Justification of Deduction [1973], p.296) | |
| A reaction: [compressed (Dummett's wordy prose cries out for it!)] I suppose this works better in mathematics, which is central to Dummett's interests. In the real world the puzzle is not usually logically implied by its explanation. |
| 2553 | The mind is a property, or it is baffling [Rorty] |
| Full Idea: All that is needed for the mind-body problem to be unintelligible is for us to be nominalist, to refuse firmly to hypostasize individual properties. | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], 1.3) | |
| A reaction: Edelman says the mind is a process rather than a property. It might vanish if the clockspeed was turned right down? Nominalism here sounds like behaviourism or instrumentalism. Would Dennett plead guilty? |
| 2550 | Pain lacks intentionality; beliefs lack qualia [Rorty] |
| Full Idea: We can't define the mental as intentional because pains aren't about anything, and we can't define it as phenomenal because beliefs don't feel like anything. | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], 1.2) | |
| A reaction: Nice, but simplistic? There is usually an intentional object for a pain, and the concepts which we use to build beliefs contain the residue of remembered qualia. It seems unlikely that any mind could have one without the other (even a computer). |
| 2554 | Is intentionality a special sort of function? [Rorty] |
| Full Idea: Following Wittgenstein, we shall treat the intentional as merely a subspecies of the functional. | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], 1.3) | |
| A reaction: Intriguing but obscure. Sounds wrong to me. The intentional refers to the content of thoughts, but function concerns their role. They have roles because they have content, so they can't be the same. |
| 2565 | Nature has no preferred way of being represented [Rorty] |
| Full Idea: Nature has no preferred way of being represented. | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], 6.5) | |
| A reaction: Tree rings accidentally represent the passing of the years. If God went back and started again would she or he opt for a 'preferred way'? |
| 2560 | Can meanings remain the same when beliefs change? [Rorty] |
| Full Idea: For cooler heads there must be some middle view between "meanings remain and beliefs change" and "meanings change whenever beliefs do". | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], 6.2) | |
| A reaction: The second one seems blatanty false. How could we otherwise explain a change in belief? But obviously some changes in belief (e.g. about electrons) produce a change in meaning. |
| 19064 | Holism is not a theory of meaning; it is the denial that a theory of meaning is possible [Dummett] |
| Full Idea: In the sense of giving a model for the content of a sentence, its representative power, holism is not a theory of meaning; it is the denial that a theory of meaning is possible. | |
| From: Michael Dummett (The Justification of Deduction [1973], p.309) | |
| A reaction: This will obviously be because sentences just don't have meaning in isolation, so their meaning can't be given in terms of the sentences. |
| 2562 | A theory of reference seems needed to pick out objects without ghostly inner states [Rorty] |
| Full Idea: The need to pick out objects without the help of definitions, essences, and meanings of terms produced, philosophers thought, a need for a "theory of reference". | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], 6.3) | |
| A reaction: Frege's was very perceptive in noting that meaning and reference are not the same. Whether we need a 'theory' of reference is unclear. It is worth describing how it occurs. |
| 2559 | Davidson's theory of meaning focuses not on terms, but on relations between sentences [Rorty] |
| Full Idea: A theory of meaning, for Davidson, is not an assemblage of "analyses" of the meanings of individual terms, but rather an understanding of the inferential relations between sentences. | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], 6.1) | |
| A reaction: Put that way, the influence of Frege on Davidson is obvious. Purely algebraic expressions can have inferential relations, using variables and formal 'sentences'. |
| 6681 | We only want to know things so that we can talk about them [Pascal] |
| Full Idea: We usually only want to know something so that we can talk about it. | |
| From: Blaise Pascal (Pensées [1662], 77 (152)) | |
| A reaction: This may be right, but I wouldn't underestimate it as a worthy end (though Pascal, as usual, calls it 'vanity'). Good talk might even be the highest human good (how many people like, more than anything, chatting in pubs?), and good talk is knowledgeable. |
| 6676 | Painting makes us admire things of which we do not admire the originals [Pascal] |
| Full Idea: How vain painting is, exciting admiration by its resemblance to things of which we do not admire the originals. | |
| From: Blaise Pascal (Pensées [1662], 40 (134)) | |
| A reaction: A lesser sort of painting simply depicts things we admire, such as a nice stretch of landscape. For Pascal it is vanity, but it could be defended as the highest achievement of art, if the purpose of artists is to make us see beauty where we had missed it. |
| 6680 | It is a funny sort of justice whose limits are marked by a river [Pascal] |
| Full Idea: It is a funny sort of justice whose limits are marked by a river; true on this side of the Pyrenees, false on the other. | |
| From: Blaise Pascal (Pensées [1662], 60 (294)) | |
| A reaction: Pascal gives nice concise summaries of our intuitions. Legal justice may be all we can actually get, but everyone knows that what happens to someone could be 'fair' on one side of a river, and very 'unfair' on the other. |
| 6677 | Imagination creates beauty, justice and happiness, which is the supreme good [Pascal] |
| Full Idea: Imagination decides everything: it creates beauty, justice and happiness, which is the world's supreme good. | |
| From: Blaise Pascal (Pensées [1662], 44 (82)) | |
| A reaction: Compare Fogelin's remark in Idea 6555. I see Pascal's point, but these ideals are also responses to facts about the world, such as human potential and human desire and successful natural functions. |
| 6678 | We live for the past or future, and so are never happy in the present [Pascal] |
| Full Idea: Our thoughts are wholly concerned with the past or the future, never with the present, which is never our end; thus we never actually live, but hope to live, and since we are always planning to be happy, it is inevitable that we should never be so. | |
| From: Blaise Pascal (Pensées [1662], 47 (172)) | |
| A reaction: A very nice expression of the importance of 'living for the moment' as a route to happiness. Personally I am occasionally startled by the thought 'Good heavens, I seem to be happy!', but it usually passes quickly. How do you plan for the present? |
| 20732 | If man considers himself as lost and imprisoned in the universe, he will be terrified [Pascal] |
| Full Idea: Let man consider what he is in comparison with what exists; let him regard himself as lost, and from this little dungeon the universe, let him learn to take the earth and himself at their proper value. Anyone considering this will be terrified at himself. | |
| From: Blaise Pascal (Pensées [1662], p.199), quoted by Kevin Aho - Existentialism: an introduction Pref 'What? | |
| A reaction: [p.199 of Penguin edn] Cited by Aho as a forerunner of existentialism. Montaigne probably influenced Pascal. Interesting that this is to be a self-inflicted existential crisis (for some purpose, probably Christian). |
| 2558 | Since Hegel we have tended to see a human as merely animal if it is outside a society [Rorty] |
| Full Idea: Only since Hegel have philosophers begun toying with the idea that the individual apart from his society is just one more animal. | |
| From: Richard Rorty (Philosophy and the Mirror of Nature [1980], 4.3) |
| 6682 | Majority opinion is visible and authoritative, although not very clever [Pascal] |
| Full Idea: Majority opinion is the best way because it can be seen, and is strong enough to command obedience, but it is the opinion of those who are least clever. | |
| From: Blaise Pascal (Pensées [1662], 85 (878)) | |
| A reaction: A nice statement of the classic dilemma faced by highly educated people over democracy. Plato preferred the clever, Aristotle agreed with Pascal, and with me. Politics must make the best of it, not pursue some ideal. Education is the one feeble hope. |
| 6679 | It is not good to be too free [Pascal] |
| Full Idea: It is not good to be too free. | |
| From: Blaise Pascal (Pensées [1662], 57 (379)) | |
| A reaction: All Americans, please take note. I agree with this, because I agree with Aristotle that man is essentially a social animal (Idea 5133), and living in a community is a matter of compromise. Extreme libertarianism contradicts our natures, and causes misery. |
| 7455 | Pascal knows you can't force belief, but you can make it much more probable [Pascal, by Hacking] |
| Full Idea: Pascal knows that one cannot decide to believe in God, but he thinks one can act so that one will very probably come to believe in God, by following a life of 'holy water and sacraments'. | |
| From: report of Blaise Pascal (Pensées [1662], 418 (233)) by Ian Hacking - The Emergence of Probability Ch.8 | |
| A reaction: This meets the most obvious and simple objection to Pascal's idea, and Pascal may well be right. I'm not sure I could resist belief after ten years in a monastery. |
| 7457 | Pascal is right, but relies on the unsupported claim of a half as the chance of God's existence [Hacking on Pascal] |
| Full Idea: Pascal's argument is valid, but it is presented with a monstrous premise of equal chance. We have no good reason for picking a half as the chance of God's existence. | |
| From: comment on Blaise Pascal (Pensées [1662], 418 (233)) by Ian Hacking - The Emergence of Probability Ch.8 | |
| A reaction: That strikes me as the last word on this rather bizarre argument. |
| 7456 | The libertine would lose a life of enjoyable sin if he chose the cloisters [Hacking on Pascal] |
| Full Idea: The libertine is giving up something if he chooses to adopt a pious form of life. He likes sin. If God is not, the worldly life is preferable to the cloistered one. | |
| From: comment on Blaise Pascal (Pensées [1662], 418 (233)) by Ian Hacking - The Emergence of Probability Ch.8 | |
| A reaction: This is a very good objection to Pascal, who seems to think you really have nothing at all to lose. I certainly don't intend to become a monk, because the chances of success seem incredibly remote from where I am sitting. |
| 6684 | If you win the wager on God's existence you win everything, if you lose you lose nothing [Pascal] |
| Full Idea: How will you wager if a coin is spun on 'Either God is or he is not'? ...If you win you win everything, if you lose you lose nothing. | |
| From: Blaise Pascal (Pensées [1662], 418 (233)) | |
| A reaction: 'Sooner safe than sorry' is a principle best used with caution. Do you really 'lose nothing' by believing a falsehood for the whole of your life? What God would reward belief on such a principles as this? |