42 ideas
| 21584 | A sense of timelessness is essential to wisdom [Russell] |
| Full Idea: Both in thought and in feeling, to realize the unimportance of time is the gate of wisdom. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 6) | |
| A reaction: A very rationalist and un-Heraclitean view of wisdom. This picture may give wisdom a bad name, if wise people are (at a minimum) at least expected to give good advice about real life. |
| 21572 | Philosophical disputes are mostly hopeless, because philosophers don't understand each other [Russell] |
| Full Idea: Explicit controversy is almost always fruitless in philosophy, owing to the fact that no two philosophers ever understand one another. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 1) | |
| A reaction: Contemporaries don't even seem to read one another very much, especially these days, when there are thousands of professional philosophers. (If you are a professional, have you read all the works written by your colleagues and friends?) |
| 21571 | Philosophical systems are interesting, but we now need a more objective scientific philosophy [Russell] |
| Full Idea: The great systems of the past serve a very useful purpose, and are abundantly worthy of study. But something different is required if philosophy is to become a science, and to aim at results independent of the tastes of the philosophers who advocate them. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], Pref) | |
| A reaction: An interesting product of this move in philosophy is (about sixty years later) the work of David Lewis, who set out to be precise and scientific, and ended up creating a very personal system. Why not a collaborative system? |
| 21574 | Hegel's confusions over 'is' show how vast systems can be built on simple errors [Russell] |
| Full Idea: Hegel's confusion of the 'is' of predication with the 'is' of identity ...is an example of how, for want of care at the start, vast and imposing systems of philosophy are built upon stupid and trivial confusions. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 2 n1) | |
| A reaction: [He explains the confusion in more detail in the note] Russell cites an English translation, and I am wondering how this occurs in the German. Plato has been accused of similar elementary blunders about properties. Russell treats Berkeley similarly. |
| 21587 | Philosophers sometimes neglect truth and distort facts to attain a nice system [Russell] |
| Full Idea: The desire for unadulterated truth is often obscured, in professional philosophers, by love of system: the one little fact which will not come inside the philosophical edifice has to be pushed and tortured until it seems to consent. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 8) | |
| A reaction: Bit of hypocrisy here. Russell was continually trying to find a system, grounded in physics and logic. Presumably his shifting views are indications of integrity, because he changes the system rather than the facts. |
| 21582 | Physicists accept particles, points and instants, while pretending they don't do metaphysics [Russell] |
| Full Idea: Physicists, ignorant and contemptuous of philosophy, have been content to assume their particles, points and instants in practice, while contending, with ironical politeness, that their concepts laid no claim to metaphysical validity. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 4) | |
| A reaction: Presumably physicists are allowed to wave their hands and utter the word 'instrumentalism', and then get on with the job. They just have to ensure they never speculate about what is being measured. |
| 21573 | When problems are analysed properly, they are either logical, or not philosophical at all [Russell] |
| Full Idea: Every philosophical problem, when it is subjected to the necessary analysis and purification, is found either to be not really philosophical at all, or else to be, in the sense in which we are using the word, logical. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 2) | |
| A reaction: [All Lecture 2 discusses 'logical'] I think Bertie was getting carried away here. In his life's corpus he barely acknowledges the existence of ethics, or political philosophy, or aesthetics. He never even engages with 'objects' the way Aristotle does. |
| 18781 | Inconsistency doesn't prevent us reasoning about some system [Mares] |
| Full Idea: We are able to reason about inconsistent beliefs, stories, and theories in useful and important ways | |
| From: Edwin D. Mares (Negation [2014], 1) |
| 18789 | Intuitionist logic looks best as natural deduction [Mares] |
| Full Idea: Intuitionist logic appears most attractive in the form of a natural deduction system. | |
| From: Edwin D. Mares (Negation [2014], 5.5) |
| 18790 | Intuitionism as natural deduction has no rule for negation [Mares] |
| Full Idea: In intuitionist logic each connective has one introduction and one elimination rule attached to it, but in the classical system we have to add an extra rule for negation. | |
| From: Edwin D. Mares (Negation [2014], 5.5) | |
| A reaction: How very intriguing. Mares says there are other ways to achieve classical logic, but they all seem rather cumbersome. |
| 18787 | Three-valued logic is useful for a theory of presupposition [Mares] |
| Full Idea: One reason for wanting a three-valued logic is to act as a basis of a theory of presupposition. | |
| From: Edwin D. Mares (Negation [2014], 3.1) | |
| A reaction: [He cites Strawson 1950] The point is that you can get a result when the presupposition does not apply, as in talk of the 'present King of France'. |
| 21588 | Logic gives the method of research in philosophy [Russell] |
| Full Idea: Logic gives the method of research in philosophy, just as mathematics gives the method in physics. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 8) | |
| A reaction: I'm struck by how rarely philosophers actually prove anything. Mostly they just use the language of logic as a tool for disambiguation. Only a tiny handful of philosophers can actually create sustained and novel proofs. |
| 18793 | Material implication (and classical logic) considers nothing but truth values for implications [Mares] |
| Full Idea: The problem with material implication, and classical logic more generally, is that it considers only the truth value of formulas in deciding whether to make an implication stand between them. It ignores everything else. | |
| From: Edwin D. Mares (Negation [2014], 7.1) | |
| A reaction: The obvious problem case is conditionals, and relevance is an obvious extra principle that comes to mind. |
| 18784 | In classical logic the connectives can be related elegantly, as in De Morgan's laws [Mares] |
| Full Idea: Among the virtues of classical logic is the fact that the connectives are related to one another in elegant ways that often involved negation. For example, De Morgan's Laws, which involve negation, disjunction and conjunction. | |
| From: Edwin D. Mares (Negation [2014], 2.2) | |
| A reaction: Mares says these enable us to take disjunction or conjunction as primitive, and then define one in terms of the other, using negation as the tool. |
| 18786 | Excluded middle standardly implies bivalence; attacks use non-contradiction, De M 3, or double negation [Mares] |
| Full Idea: On its standard reading, excluded middle tells us that bivalence holds. To reject excluded middle, we must reject either non-contradiction, or ¬(A∧B) ↔ (¬A∨¬B) [De Morgan 3], or the principle of double negation. All have been tried. | |
| From: Edwin D. Mares (Negation [2014], 2.2) |
| 18780 | Standard disjunction and negation force us to accept the principle of bivalence [Mares] |
| Full Idea: If we treat disjunction in the standard way and take the negation of a statement A to mean that A is false, accepting excluded middle forces us also to accept the principle of bivalence, which is the dictum that every statement is either true or false. | |
| From: Edwin D. Mares (Negation [2014], 1) | |
| A reaction: Mates's point is to show that passively taking the normal account of negation for granted has important implications. |
| 21586 | The logical connectives are not objects, but are formal, and need a context [Russell] |
| Full Idea: Such words as 'or' and 'not' are not names of definite objects, but are words that require a context in order to have a meaning. All of them are formal. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 7) | |
| A reaction: [He cites Wittgenstein's 1922 Tractatus in a footnote - presumably in a later edition than 1914] This is the most famous idea which Russell acquired from Wittgenstein. It was yet another step in his scaling down of ontology. |
| 18782 | The connectives are studied either through model theory or through proof theory [Mares] |
| Full Idea: In studying the logical connectives, philosophers of logic typically adopt the perspective of either model theory (givng truth conditions of various parts of the language), or of proof theory (where use in a proof system gives the connective's meaning). | |
| From: Edwin D. Mares (Negation [2014], 1) | |
| A reaction: [compressed] The commonest proof theory is natural deduction, giving rules for introduction and elimination. Mates suggests moving between the two views is illuminating. |
| 18783 | Many-valued logics lack a natural deduction system [Mares] |
| Full Idea: Many-valued logics do not have reasonable natural deduction systems. | |
| From: Edwin D. Mares (Negation [2014], 1) |
| 18792 | Situation semantics for logics: not possible worlds, but information in situations [Mares] |
| Full Idea: Situation semantics for logics consider not what is true in worlds, but what information is contained in situations. | |
| From: Edwin D. Mares (Negation [2014], 6.2) | |
| A reaction: Since many theoretical physicists seem to think that 'information' might be the most basic concept of a natural ontology, this proposal is obviously rather appealing. Barwise and Perry are the authors of the theory. |
| 18785 | Consistency is semantic, but non-contradiction is syntactic [Mares] |
| Full Idea: The difference between the principle of consistency and the principle of non-contradiction is that the former must be stated in a semantic metalanguage, whereas the latter is a thesis of logical systems. | |
| From: Edwin D. Mares (Negation [2014], 2.2) |
| 21585 | The tortoise won't win, because infinite instants don't compose an infinitely long time [Russell] |
| Full Idea: The idea that an infinite number of instants make up an infinitely long time is not true, and therefore the conclusion that Achilles will never overtake the tortoise does not follow. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 6) | |
| A reaction: Aristotle spotted this, but didn't express it as clearly as Russell. |
| 18788 | For intuitionists there are not numbers and sets, but processes of counting and collecting [Mares] |
| Full Idea: For the intuitionist, talk of mathematical objects is rather misleading. For them, there really isn't anything that we should call the natural numbers, but instead there is counting. What intuitionists study are processes, such as counting and collecting. | |
| From: Edwin D. Mares (Negation [2014], 5.1) | |
| A reaction: That is the first time I have seen mathematical intuitionism described in a way that made it seem attractive. One might compare it to a metaphysics based on processes. Apparently intuitionists struggle with infinite sets and real numbers. |
| 14664 | Necessary beings (numbers, properties, sets, propositions, states of affairs, God) exist in all possible worlds [Plantinga] |
| Full Idea: A 'necessary being' is one that exists in every possible world; and only some objects - numbers, properties, pure sets, propositions, states of affairs, God - have this distinction. | |
| From: Alvin Plantinga (Actualism and Possible Worlds [1976], 2) | |
| A reaction: This a very odd list, though it is fairly orthodox among philosophers trained in modern modal logic. At the very least it looks rather parochial to me. |
| 21684 | Atomic facts may be inferrable from others, but never from non-atomic facts [Russell] |
| Full Idea: Perhaps one atomic fact may sometimes be capable of being inferred from another, though I do not believe this to be the case; but in any case it cannot be inferred from premises no one of which is an atomic fact. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], p.48) | |
| A reaction: I prefer Russell's caution to Wittgenstein's dogmatism. I presume utterly simple facts give you nothing to work with. Hegel thought that you could infer new concepts from given concepts. |
| 22316 | A positive and negative fact have the same constituents; their difference is primitive [Russell] |
| Full Idea: It must not be supposed that a negative fact contains a constituent corresponding to the word 'not'. It contains no more constituents than a positive fact of the correlative positive form. The differenece between the two forms is ultimate and irreducible. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], VIII.279), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 41 'Neg' | |
| A reaction: ['Harvard Lectures'] The audience disliked this. How does one fact exclude the other fact? Potter asks whether absence is a fact, and whether an absence can be a truthmaker. |
| 21576 | With asymmetrical relations (before/after) the reduction to properties is impossible [Russell] |
| Full Idea: When we come to asymmetrical relations, such as before and after, greater and less etc., the attempt to reduce them to properties becomes obviously impossible. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 2) | |
| A reaction: The traditional Aristotelian reduction to properties is attributed by Russell to logic based on subject-predicate. As an example he cites being greater than as depending on more than the mere magnitudes of the entities. Direction of the relation. |
| 21575 | When we attribute a common quality to a group, we can forget the quality and just talk of the group [Russell] |
| Full Idea: When a group of objects have the similarity we are inclined to attribute to possession of a common quality, the membership of the group will serve all the purposes of the supposed common quality ...which need not be assumed to exist. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 2) | |
| A reaction: This is the earliest account I have found of properties being treated as sets of objects. It more or less coincides with the invention of set theory. I am reminded of Idea 9208. What is the bazzing property? It's what those three things have in common. |
| 14666 | Socrates is a contingent being, but his essence is not; without Socrates, his essence is unexemplified [Plantinga] |
| Full Idea: Socrates is a contingent being; his essence, however, is not. Properties, like propositions and possible worlds, are necessary beings. If Socrates had not existed, his essence would have been unexemplified, but not non-existent. | |
| From: Alvin Plantinga (Actualism and Possible Worlds [1976], 4) | |
| A reaction: This is a distinctive Plantinga view, of which I can make little sense. I take it that Socrates used to have an essence. Being dead, the essence no longer exists, but when we talk about Socrates it is largely this essence to which we refer. OK? |
| 14662 | Possible worlds clarify possibility, propositions, properties, sets, counterfacts, time, determinism etc. [Plantinga] |
| Full Idea: The idea of possible worlds has delivered insights on logical possibility (de dicto and de re), propositions, properties and sets, counterfactuals, time and temporal relations, causal determinism, the ontological argument, and the problem of evil. | |
| From: Alvin Plantinga (Actualism and Possible Worlds [1976], Intro) | |
| A reaction: This date (1976) seems to be the high-water mark for enthusiasm about possible worlds. I suppose if we just stick to 'insights' rather than 'answers' then the big claim might still be acceptable. Which problems are created by possible worlds? |
| 16472 | Plantinga's actualism is nominal, because he fills actuality with possibilia [Stalnaker on Plantinga] |
| Full Idea: Plantinga's critics worry that the metaphysics is actualist in name only, since it is achieved only by populating the actual world with entities whose nature is explained in terms of merely possible things that would exemplify them if anything did. | |
| From: comment on Alvin Plantinga (Actualism and Possible Worlds [1976]) by Robert C. Stalnaker - Mere Possibilities 4.4 | |
| A reaction: Plantinga seems a long way from the usual motivation for actualism, which is probably sceptical empiricism, and building a system on what is smack in front of you. Possibilities have to be true, though. That's why you need dispositions in actuality. |
| 21580 | Science condemns sense-data and accepts matter, but a logical construction must link them [Russell] |
| Full Idea: Men of science condemn immediate data as 'merely subjective', while maintaining the truths of physics from those data. ...The only justification possible for this must be one which exhibits matter as a logical construction from sense-data. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 4) | |
| A reaction: Since we blatantly aren't doing logic when we stare out of the window, this aspires to finding something like the 'logical form' of perception. |
| 21583 | When sense-data change, there must be indistinguishable sense-data in the process [Russell] |
| Full Idea: In all cases of sense-data capable of gradual change, we may find one sense-datum indistinguishable from another, and that indistinguishable from a third, while yet the first and third are quite easily distinguishable. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 5) | |
| A reaction: This point is key to the sense-data theory, because it gives them independent existence, standing between reality and subjective experience. It is also the reason why they look increasingly implausible, if they may not be experienced. |
| 21577 | Empirical truths are particular, so general truths need an a priori input of generality [Russell] |
| Full Idea: All empirical evidence is of particular truths. Hence, if there is any knowledge of general truths at all, there must be some knowledge of general truths which is independent of empirical evidence. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 2) | |
| A reaction: Humean empiricists respond by being a sceptical of general truths. At this stage of his career Russell looks like a thoroughgoing rationalist, and he believes in the reality of universals, relations and propositions. He became more empirical later. |
| 21579 | Objects are treated as real when they connect with other experiences in a normal way [Russell] |
| Full Idea: Objects of sense are called 'real' when they have the kind of connection with other objects of sense which experience has led us to regard as normal; when they fail this, they are called 'illusions'. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 3) | |
| A reaction: This rests rather too much on the concept of 'normal', but offers an attractive coherence account of perception. Direct perceptions are often invoked by anti-coherentists, but I think coherence is just as much needed in that realm. |
| 21578 | Global scepticism is irrefutable, but can't replace our other beliefs, and just makes us hesitate [Russell] |
| Full Idea: Universal scepticism, though logically irrefutable, is practically barren; it can only, therefore, give a certain flavour of hesitancy to our beliefs, and cannot be used to substitute other beliefs for them. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 3) | |
| A reaction: Spot on. There is no positive evidence for scepticism, so must just register it as the faintest of possibilities, like the existence of secretive fairies. |
| 6416 | Other minds seem to exist, because their testimony supports realism about the world [Russell, by Grayling] |
| Full Idea: Russell gives an argument that other minds exist, because if one is entitled to believe this, then one can rely on the testimony of others, which, jointly with one's own experience, will give powerful support to the view that there a real spatial world. | |
| From: report of Bertrand Russell (Our Knowledge of the External World [1914], 3) by A.C. Grayling - Russell Ch.2 | |
| A reaction: I rather like this argument. It is quite close to Wittgenstein's Private Language Argument, which also seems to refute scepticism about other minds. I think Russell's line, using testimony, knowledge and realism, may be better than Wittgenstein's. |
| 18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
| Full Idea: In 'situation semantics' individuals, properties, facts, and events are treated as abstractions from situations. | |
| From: Edwin D. Mares (Negation [2014], 6.1) | |
| A reaction: [Barwise and Perry 1983 are cited] Since I take the process of abstraction to be basic to thought, I am delighted to learn that someone has developed a formal theory based on it. I am immediately sympathetic to situation semantics. |
| 16469 | Plantinga has domains of sets of essences, variables denoting essences, and predicates as functions [Plantinga, by Stalnaker] |
| Full Idea: The domains in Plantinga's interpretation of Kripke's semantics are sets of essences, and the values of variables are essences. The values of predicates have to be functions from possible worlds to essences. | |
| From: report of Alvin Plantinga (Actualism and Possible Worlds [1976]) by Robert C. Stalnaker - Mere Possibilities 4.4 | |
| A reaction: I begin to think this is quite nice, as long as one doesn't take the commitment to the essences too seriously. For 'essence' read 'minimal identity'? But I take essences to be more than minimal, so use identities (which Kripke does?). |
| 16470 | Plantinga's essences have their own properties - so will have essences, giving a hierarchy [Stalnaker on Plantinga] |
| Full Idea: For Plantinga, essences are entities in their own right and will have properties different from what instantiates them. Hence he will need individual essences of individual essences, distinct from the essences. I see no way to avoid a hierarchy of them. | |
| From: comment on Alvin Plantinga (Actualism and Possible Worlds [1976]) by Robert C. Stalnaker - Mere Possibilities 4.4 | |
| A reaction: This sounds devastating for Plantinga, but it is a challenge for traditional Aristotelians. Only a logician suffers from a hierarchy, but a scientist might have to live with an essence, which contains a super-essence. |
| 14663 | Are propositions and states of affairs two separate things, or only one? I incline to say one [Plantinga] |
| Full Idea: Are there two sorts of thing, propositions and states of affairs, or only one? I am inclined to the former view on the ground that propositions have a property, truth or falsehood, not had by states of affairs. | |
| From: Alvin Plantinga (Actualism and Possible Worlds [1976], 1) | |
| A reaction: Might a proposition be nothing more than an assertion that a state of affairs obtains? It would then pass his test. The idea that a proposition is a complex of facts in the external world ('Russellian' propositions?) quite baffles me. |
| 21581 | We never experience times, but only succession of events [Russell] |
| Full Idea: There is no reason in experience to suppose that there are times as opposed to events: the events, ordered by the relations of simultaneity and succession, are all that experience provides. | |
| From: Bertrand Russell (Our Knowledge of the External World [1914], 4) | |
| A reaction: We experience events, but also have quite an accurate sense of how much time has passed during the occurrence of events. If asked how much time has lapsed, why don't we say '32 events'? How do we distinguish long events from short ones? |