34 ideas
| 1798 | He studied philosophy by suspending his judgement on everything [Pyrrho, by Diog. Laertius] |
| Full Idea: He studied philosophy on the principle of suspending his judgement on all points. | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.3 | |
| A reaction: In what sense was Pyrrho a philosopher, then? He must have asserted SOME generalised judgments. |
| 6118 | Philosophy is logical analysis, followed by synthesis [Russell] |
| Full Idea: The business of philosophy, as I conceive it, is essentially that of logical analysis, followed by logical synthesis. | |
| From: Bertrand Russell (Logical Atomism [1924], p.162) | |
| A reaction: I am uneasy about Russell's hopes for the contribution that logic could make, but I totally agree that analysis is the route to wisdom, and I take Aristotle as my role model of an analytical philosopher, rather than the modern philosophers of logic. |
| 6116 | A logical language would show up the fallacy of inferring reality from ordinary language [Russell] |
| Full Idea: We are trying to create a perfectly logical language to prevent inferences from the nature of language to the nature of the world, which are fallacious because they depend upon the logical defects of language. | |
| From: Bertrand Russell (Logical Atomism [1924], p.159) | |
| A reaction: Wittgenstein seems to have rebelled against this idea, so that one strand of his later philosophy leads to 'ordinary language' philosophy, which is exactly what Russell is criticising. Wittgenstein seems to have seen 'logical language' as an oxymoron. |
| 6117 | Philosophy should be built on science, to reduce error [Russell] |
| Full Idea: We would be wise to build our philosophy upon science, because the risk of error in philosophy is pretty sure to be greater than in science. | |
| From: Bertrand Russell (Logical Atomism [1924], p.160) | |
| A reaction: If you do very little, it reduces the 'risk of error'. I agree that philosophers should start from the facts, and be responsive to new facts, and that science is excellent at discovering facts. But I don't think cognitive science is the new epistemology. |
| 1800 | Sceptics say reason is only an instrument, because reason can only be attacked with reason [Pyrrho, by Diog. Laertius] |
| Full Idea: The Sceptics say that they only employ reason as an instrument, because it is impossible to overturn the authority of reason, without employing reason. | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.8 |
| 6110 | Subject-predicate logic (and substance-attribute metaphysics) arise from Aryan languages [Russell] |
| Full Idea: It is doubtful whether the subject-predicate logic, with the substance-attribute metaphysic, would have been invented by people speaking a non-Aryan language. | |
| From: Bertrand Russell (Logical Atomism [1924], p.151) | |
| A reaction: This is not far off the Sapir-Whorf Hypothesis (e.g. Idea 3917), which Russell would never accept. I presume that Russell would see true logic as running deeper, and the 'Aryan' approach as just one possible way to describe it. |
| 6107 | It is logic, not metaphysics, that is fundamental to philosophy [Russell] |
| Full Idea: I hold that logic is what is fundamental in philosophy, and that schools should be characterised rather by their logic than by their metaphysics. | |
| From: Bertrand Russell (Logical Atomism [1924], p.143) | |
| A reaction: Personally I disagree. Russell seems to have been most interested in the logical form underlying language, but that seems to be because he was interested in the ontological implications of what we say, which is metaphysics. |
| 6115 | Vagueness, and simples being beyond experience, are obstacles to a logical language [Russell] |
| Full Idea: The fact that we do not experience simples is one obstacle to the actual creation of a correct logical language, and vagueness is another. | |
| From: Bertrand Russell (Logical Atomism [1924], p.159) | |
| A reaction: The dream of creating a perfect logical language looks doomed from the start, but it is a very interesting project to try to pinpoint why it is unlikely to be possible. I say a perfect language cuts nature exactly at the joints, so find the joints. |
| 6109 | Some axioms may only become accepted when they lead to obvious conclusions [Russell] |
| Full Idea: Some of the premisses (of my logicist theory) are much less obvious than some of their consequences, and are believed chiefly because of their consequences. This will be found to be always the case when a science is arranged as a deductive system. | |
| From: Bertrand Russell (Logical Atomism [1924], p.145) | |
| A reaction: We shouldn't assume the model of self-evident axioms leading to surprising conclusions, which is something like the standard model for rationalist foundationalists. Russell nicely points out that the situation could be just the opposite |
| 8698 | Modal structuralism says mathematics studies possible structures, which may or may not be actualised [Hellman, by Friend] |
| Full Idea: The modal structuralist thinks of mathematical structures as possibilities. The application of mathematics is just the realisation that a possible structure is actualised. As structures are possibilities, realist ontological problems are avoided. | |
| From: report of Geoffrey Hellman (Mathematics without Numbers [1989]) by Michèle Friend - Introducing the Philosophy of Mathematics 4.3 | |
| A reaction: Friend criticises this and rejects it, but it is appealing. Mathematics should aim to be applicable to any possible world, and not just the actual one. However, does the actual world 'actualise a mathematical structure'? |
| 9557 | Statements of pure mathematics are elliptical for a sort of modal conditional [Hellman, by Chihara] |
| Full Idea: Hellman represents statements of pure mathematics as elliptical for modal conditionals of a certain sort. | |
| From: report of Geoffrey Hellman (Mathematics without Numbers [1989]) by Charles Chihara - A Structural Account of Mathematics 5.3 | |
| A reaction: It's a pity there is such difficulty in understanding conditionals (see Graham Priest on the subject). I intuit a grain of truth in this, though I take maths to reflect the structure of the actual world (with possibilities being part of that world). |
| 10263 | Modal structuralism can only judge possibility by 'possible' models [Shapiro on Hellman] |
| Full Idea: The usual way to show that a sentence is possible is to show that it has a model, but for Hellman presumably a sentence is possible if it might have a model (or if, possibly, it has a model). It is not clear what this move brings us. | |
| From: comment on Geoffrey Hellman (Mathematics without Numbers [1989]) by Stewart Shapiro - Philosophy of Mathematics 7.3 | |
| A reaction: I can't assess this, but presumably the possibility of the model must be demonstrated in some way. Aren't all models merely possible, because they are based on axioms, which seem to be no more than possibilities? |
| 6108 | Maths can be deduced from logical axioms and the logic of relations [Russell] |
| Full Idea: I think that no one will dispute that from certain ideas and axioms of formal logic, but with the help of the logic of relations, all pure mathematics can be deduced. | |
| From: Bertrand Russell (Logical Atomism [1924], p.145) | |
| A reaction: It has been said for a long time that Gödel's Incompleteness Theorems of 1930 disproved this claim, though recently there have been defenders of logicism. Beginning with 'certain ideas' sounds like begging the question. |
| 10968 | Russell gave up logical atomism because of negative, general and belief propositions [Russell, by Read] |
| Full Idea: Russell preceded Wittgenstein in deciding that the reduction of all propositions to atomic propositions could not be achieved. The problem cases were negative propositions, general propositions, and belief propositions. | |
| From: report of Bertrand Russell (Logical Atomism [1924]) by Stephen Read - Thinking About Logic Ch.1 |
| 6113 | To mean facts we assert them; to mean simples we name them [Russell] |
| Full Idea: The way to mean a fact is to assert it; the way to mean a simple is to name it. | |
| From: Bertrand Russell (Logical Atomism [1924], p.156) | |
| A reaction: Thus logical atomism is a linguistic programme, of reducing our language to a foundation of pure names. The recent thought of McDowell and others is aimed at undermining any possibility of a 'simple' in perception. The myth of 'The Given'. |
| 6114 | 'Simples' are not experienced, but are inferred at the limits of analysis [Russell] |
| Full Idea: When I speak of 'simples' I am speaking of something not experienced as such, but known only inferentially as the limits of analysis. | |
| From: Bertrand Russell (Logical Atomism [1924], p.158) | |
| A reaction: He claims that the simples are 'known', so he does not mean purely theoretical entities. They have something like the status of quarks in physics, whose existence is inferred from experience. |
| 21722 | Better to construct from what is known, than to infer what is unknown [Russell] |
| Full Idea: Whenever possible, substitute constructions out of known entities for inferences to unknown entities. | |
| From: Bertrand Russell (Logical Atomism [1924], p.161), quoted by Bernard Linsky - Russell's Metaphysical Logic 7 | |
| A reaction: In 1919 he said that the alternative, of 'postulating' new entities, has 'all the advantages of theft over honest toil' [IMP p.71]. This is Russell's commitment to 'constructing' everything, even his concept of matter. Arithmetic as PA is postulation. |
| 6111 | As propositions can be put in subject-predicate form, we wrongly infer that facts have substance-quality form [Russell] |
| Full Idea: Since any proposition can be put into a form with a subject and a predicate, united by a copula, it is natural to infer that every fact consists in the possession of a quality by a substance, which seems to me a mistake. | |
| From: Bertrand Russell (Logical Atomism [1924], p.152) | |
| A reaction: This disagrees with McGinn on facts (Idea 6075). I approve of this warning from Russell, which is a recognition that we can't just infer our metaphysics from our language. I think of this as the 'Frege Fallacy', which ensnared Quine and others. |
| 6595 | If we need a criterion of truth, we need to know whether it is the correct criterion [Pyrrho, by Fogelin] |
| Full Idea: Against the Stoics, the Pyrrhonians argued that if someone presents a criterion of truth, then it will be important to determine whether it is the correct criterion. | |
| From: report of Pyrrho (reports [c.325 BCE]) by Robert Fogelin - Walking the Tightrope of Reason Ch.4 | |
| A reaction: Hence Davidson says that attempts to define truth are 'folly'. If something has to be taken as basic, then truth seems a good candidate (since, for example, logical operators could not otherwise be defined by means of 'truth' tables). |
| 6593 | The Pyrrhonians attacked the dogmas of professors, not ordinary people [Pyrrho, by Fogelin] |
| Full Idea: The attacks of the Pyrrhonian sceptics are directed against the dogmas of the 'professors', not against the beliefs of the common people pursuing the business of daily life. | |
| From: report of Pyrrho (reports [c.325 BCE]) by Robert Fogelin - Walking the Tightrope of Reason Ch.4 | |
| A reaction: This may be because they thought that ordinary people were too confused to be worth attacking, rather than because they lived in a state of beautifully appropriate beliefs. Naïve realism is certainly worth attacking. |
| 6592 | Academics said that Pyrrhonians were guilty of 'negative dogmatism' [Pyrrho, by Fogelin] |
| Full Idea: The ancient Academic sceptics charged the Pyrrhonian sceptics with 'negative dogmatism' when they claimed that a certain kind of knowledge is impossible. | |
| From: report of Pyrrho (reports [c.325 BCE]) by Robert Fogelin - Walking the Tightrope of Reason Ch.4 | |
| A reaction: It is this kind of point which should push us towards some sort of rationalism, because certain a priori 'dogmas' seem to be indispensable to get any sort of discussion off the ground. The only safe person is Cratylus (see Idea 578). |
| 1801 | Animals vary in their feelings and judgements (Mode 1) [Pyrrho, by Diog. Laertius] |
| Full Idea: First mode: animals vary in their feelings and judgements (of food, for example). | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.9 |
| 1805 | Judgements vary according to local culture and law (Mode 5) [Pyrrho, by Diog. Laertius] |
| Full Idea: Fifth mode: judgements vary according to local custom, law and culture (Persians marry their daughters). | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.9 |
| 1808 | Perception of things depends on their size or quantity (Mode 8) [Pyrrho, by Diog. Laertius] |
| Full Idea: Eighth mode: perceptions of things depend on their magnitude or quantity (food and wine). | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.9 |
| 1804 | Perception varies with madness or disease (Mode 4) [Pyrrho, by Diog. Laertius] |
| Full Idea: Fourth mode: perceivers vary in their mental and physical state (such as the mad and the sick). | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.9 |
| 1806 | Perception of objects depends on surrounding conditions (Mode 6) [Pyrrho, by Diog. Laertius] |
| Full Idea: Sixth mode: the perception of an object depends on surrounding conditions (sunlight and lamplight). | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.9 |
| 1803 | Objects vary according to which sense perceives them (Mode 3) [Pyrrho, by Diog. Laertius] |
| Full Idea: Third mode: things like an apple vary according to which sense perceives them (yellow, sweet, and fragrant). | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.9 |
| 1809 | Perception is affected by expectations (Mode 9) [Pyrrho, by Diog. Laertius] |
| Full Idea: Ninth mode: we perceive things according to what we expect (earthquakes and sunshine). | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.9 |
| 1802 | Individuals vary in responses and feelings (Mode 2) [Pyrrho, by Diog. Laertius] |
| Full Idea: Second mode: individual men vary in responses and feelings (heat and cold, for example). | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.9 |
| 1807 | Perception varies with viewing distance and angle (Mode 7) [Pyrrho, by Diog. Laertius] |
| Full Idea: Seventh mode: perception varies according to viewing distance and angle (the sun, and a dove's neck). | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.9 |
| 1810 | Perception and judgement depend on comparison (Mode 10) [Pyrrho, by Diog. Laertius] |
| Full Idea: Tenth mode: perceptions and judgements depend on comparison (light/heavy, above/below). | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.Py.9 |
| 6112 | Meaning takes many different forms, depending on different logical types [Russell] |
| Full Idea: There is not one relation of meaning between words and what they stand for, but as many relations of meaning, each of a different logical type, as there are logical types among the objects for which there are words. | |
| From: Bertrand Russell (Logical Atomism [1924], p.153) | |
| A reaction: This might be a good warning for those engaged in the externalist/internalist debate over the meaning of concepts such as natural kind terms like 'water'. I could have an external meaning for 'elms', but an internal meaning for 'ferns'. |
| 3062 | There are no causes, because they are relative, and alike things can't cause one another [Pyrrho, by Diog. Laertius] |
| Full Idea: The idea of cause is relative to that of which it is the cause, and so has no real existence. …Also cause must either be body causing body, or incorporeal causing incorporeal, and neither of these is possible. | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.11.11 |
| 3063 | Motion can't move where it is, and can't move where it isn't, so it can't exist [Pyrrho, by Diog. Laertius] |
| Full Idea: Motion is not moved in the place in which it is is, and it is impossible that it should be moved in the place in which it is not, so there is no such thing as motion. | |
| From: report of Pyrrho (reports [c.325 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.11.11 |