87 ideas
| 6095 | The business of metaphysics is to describe the world [Russell] |
| 14456 | 'Socrates is human' expresses predication, and 'Socrates is a man' expresses identity [Russell] |
| 6106 | Reducing entities and premisses makes error less likely [Russell] |
| 14426 | A definition by 'extension' enumerates items, and one by 'intension' gives a defining property [Russell] |
| 8468 | The sentence 'procrastination drinks quadruplicity' is meaningless, rather than false [Russell, by Orenstein] |
| 6090 | Facts make propositions true or false, and are expressed by whole sentences [Russell] |
| 18348 | Not only atomic truths, but also general and negative truths, have truth-makers [Russell, by Rami] |
| 14454 | An argument 'satisfies' a function φx if φa is true [Russell] |
| 14453 | The Darapti syllogism is fallacious: All M is S, all M is P, so some S is P' - but if there is no M? [Russell] |
| 6103 | Normally a class with only one member is a problem, because the class and the member are identical [Russell] |
| 14427 | We can enumerate finite classes, but an intensional definition is needed for infinite classes [Russell] |
| 14428 | Members define a unique class, whereas defining characteristics are numerous [Russell] |
| 14447 | Infinity says 'for any inductive cardinal, there is a class having that many terms' [Russell] |
| 14440 | We may assume that there are infinite collections, as there is no logical reason against them [Russell] |
| 14443 | The British parliament has one representative selected from each constituency [Russell] |
| 14445 | Choice shows that if any two cardinals are not equal, one must be the greater [Russell] |
| 14444 | Choice is equivalent to the proposition that every class is well-ordered [Russell] |
| 14446 | We can pick all the right or left boots, but socks need Choice to insure the representative class [Russell] |
| 14459 | Reducibility: a family of functions is equivalent to a single type of function [Russell] |
| 14461 | Propositions about classes can be reduced to propositions about their defining functions [Russell] |
| 8469 | Russell's proposal was that only meaningful predicates have sets as their extensions [Russell, by Orenstein] |
| 8745 | Classes are logical fictions, and are not part of the ultimate furniture of the world [Russell] |
| 14452 | All the propositions of logic are completely general [Russell] |
| 14462 | In modern times, logic has become mathematical, and mathematics has become logical [Russell] |
| 14464 | Logic can be known a priori, without study of the actual world [Russell] |
| 10057 | Logic can only assert hypothetical existence [Russell] |
| 12444 | Logic is concerned with the real world just as truly as zoology [Russell] |
| 6092 | In a logically perfect language, there will be just one word for every simple object [Russell] |
| 6101 | Romulus does not occur in the proposition 'Romulus did not exist' [Russell] |
| 6102 | You can understand 'author of Waverley', but to understand 'Scott' you must know who it applies to [Russell] |
| 10423 | There are a set of criteria for pinning down a logically proper name [Russell, by Sainsbury] |
| 14458 | Asking 'Did Homer exist?' is employing an abbreviated description [Russell] |
| 7744 | Treat description using quantifiers, and treat proper names as descriptions [Russell, by McCullogh] |
| 10450 | Russell admitted that even names could also be used as descriptions [Russell, by Bach] |
| 14457 | Names are really descriptions, except for a few words like 'this' and 'that' [Russell] |
| 10426 | A name has got to name something or it is not a name [Russell] |
| 7311 | The only genuine proper names are 'this' and 'that' [Russell] |
| 14455 | 'I met a unicorn' is meaningful, and so is 'unicorn', but 'a unicorn' is not [Russell] |
| 14442 | If straight lines were like ratios they might intersect at a 'gap', and have no point in common [Russell] |
| 14438 | New numbers solve problems: negatives for subtraction, fractions for division, complex for equations [Russell] |
| 13510 | Could a number just be something which occurs in a progression? [Russell, by Hart,WD] |
| 14436 | A series can be 'Cut' in two, where the lower class has no maximum, the upper no minimum [Russell] |
| 14439 | A complex number is simply an ordered couple of real numbers [Russell] |
| 14421 | Discovering that 1 is a number was difficult [Russell] |
| 14424 | Numbers are needed for counting, so they need a meaning, and not just formal properties [Russell] |
| 14441 | The formal laws of arithmetic are the Commutative, the Associative and the Distributive [Russell] |
| 14420 | Infinity and continuity used to be philosophy, but are now mathematics [Russell] |
| 14431 | The definition of order needs a transitive relation, to leap over infinite intermediate terms [Russell] |
| 14422 | Any founded, non-repeating series all reachable in steps will satisfy Peano's axioms [Russell] |
| 14423 | '0', 'number' and 'successor' cannot be defined by Peano's axioms [Russell] |
| 14425 | A number is something which characterises collections of the same size [Russell] |
| 14434 | What matters is the logical interrelation of mathematical terms, not their intrinsic nature [Russell] |
| 14465 | Maybe numbers are adjectives, since 'ten men' grammatically resembles 'white men' [Russell] |
| 13414 | For Russell, numbers are sets of equivalent sets [Russell, by Benacerraf] |
| 6104 | Numbers are classes of classes, and hence fictions of fictions [Russell] |
| 14449 | There is always something psychological about inference [Russell] |
| 14463 | Existence can only be asserted of something described, not of something named [Russell] |
| 21708 | Russell's new logical atomist was of particulars, universals and facts (not platonic propositions) [Russell, by Linsky,B] |
| 19051 | Russell's atomic facts are actually compounds, and his true logical atoms are sense data [Russell, by Quine] |
| 6089 | Logical atomism aims at logical atoms as the last residue of analysis [Russell] |
| 6100 | Once you have enumerated all the atomic facts, there is a further fact that those are all the facts [Russell] |
| 6105 | Logical atoms aims to get down to ultimate simples, with their own unique reality [Russell] |
| 14429 | Classes are logical fictions, made from defining characteristics [Russell] |
| 21709 | You can't name all the facts, so they are not real, but are what propositions assert [Russell] |
| 18376 | Russell asserts atomic, existential, negative and general facts [Russell, by Armstrong] |
| 5465 | Modern trope theory tries, like logical atomism, to reduce things to elementary states [Russell, by Ellis] |
| 6060 | 'Existence' means that a propositional function is sometimes true [Russell] |
| 14430 | If a relation is symmetrical and transitive, it has to be reflexive [Russell] |
| 14432 | 'Asymmetry' is incompatible with its converse; a is husband of b, so b can't be husband of a [Russell] |
| 14435 | The essence of individuality is beyond description, and hence irrelevant to science [Russell] |
| 6099 | Modal terms are properties of propositional functions, not of propositions [Russell] |
| 12197 | Inferring q from p only needs p to be true, and 'not-p or q' to be true [Russell] |
| 14450 | All forms of implication are expressible as truth-functions [Russell] |
| 14460 | If something is true in all possible worlds then it is logically necessary [Russell] |
| 6098 | Perception goes straight to the fact, and not through the proposition [Russell] |
| 14433 | Mathematically expressed propositions are true of the world, but how to interpret them? [Russell] |
| 6097 | The theory of error seems to need the existence of the non-existent [Russell] |
| 9022 | Russell uses 'propositional function' to refer to both predicates and to attributes [Quine on Russell] |
| 6091 | Propositions don't name facts, because each fact corresponds to a proposition and its negation [Russell] |
| 14451 | Propositions are mainly verbal expressions of true or false, and perhaps also symbolic thoughts [Russell] |
| 21702 | In 1918 still believes in nonlinguistic analogues of sentences, but he now calls them 'facts' [Russell, by Quine] |
| 6094 | An inventory of the world does not need to include propositions [Russell] |
| 6096 | I no longer believe in propositions, especially concerning falsehoods [Russell] |
| 21712 | I know longer believe in shadowy things like 'that today is Wednesday' when it is actually Tuesday [Russell] |
| 6093 | The names in a logically perfect language would be private, and could not be shared [Russell] |
| 6017 | Nomos is king [Pindar] |
| 6119 | You can discuss 'God exists', so 'God' is a description, not a name [Russell] |