137 ideas
14122 | Analysis gives us nothing but the truth - but never the whole truth [Russell] |
14109 | The study of grammar is underestimated in philosophy [Russell] |
14165 | Analysis falsifies, if when the parts are broken down they are not equivalent to their sum [Russell] |
14115 | Definition by analysis into constituents is useless, because it neglects the whole [Russell] |
14159 | In mathematics definitions are superfluous, as they name classes, and it all reduces to primitives [Russell] |
14148 | Infinite regresses have propositions made of propositions etc, with the key term reappearing [Russell] |
18002 | As well as a truth value, propositions have a range of significance for their variables [Russell] |
14102 | What is true or false is not mental, and is best called 'propositions' [Russell] |
18335 | There are five problems which the truth-maker theory might solve [Rami] |
18334 | The truth-maker idea is usually justified by its explanatory power, or intuitive appeal [Rami] |
18339 | The truth-making relation can be one-to-one, or many-to-many [Rami] |
18333 | Central idea: truths need truthmakers; and possibly all truths have them, and makers entail truths [Rami] |
18342 | Most theorists say that truth-makers necessitate their truths [Rami] |
18340 | It seems best to assume different kinds of truth-maker, such as objects, facts, tropes, or events [Rami] |
18341 | Truth-makers seem to be states of affairs (plus optional individuals), or individuals and properties [Rami] |
18346 | 'Truth supervenes on being' only gives necessary (not sufficient) conditions for contingent truths [Rami] |
18345 | 'Truth supervenes on being' avoids entities as truth-makers for negative truths [Rami] |
18343 | Maybe a truth-maker also works for the entailments of the given truth [Rami] |
18338 | Truth-making is usually internalist, but the correspondence theory is externalist [Rami] |
18337 | Correspondence theories assume that truth is a representation relation [Rami] |
14176 | "The death of Caesar is true" is not the same proposition as "Caesar died" [Russell] |
18347 | Deflationist truth is an infinitely disjunctive property [Rami] |
18350 | Truth-maker theorists should probably reject the converse Barcan formula [Rami] |
14113 | The null class is a fiction [Russell] |
15894 | Russell invented the naïve set theory usually attributed to Cantor [Russell, by Lavine] |
14126 | Order rests on 'between' and 'separation' [Russell] |
14127 | Order depends on transitive asymmetrical relations [Russell] |
14121 | The part-whole relation is ultimate and indefinable [Russell] |
14106 | Implication cannot be defined [Russell] |
14108 | It would be circular to use 'if' and 'then' to define material implication [Russell] |
14167 | The only classes are things, predicates and relations [Russell] |
14105 | There seem to be eight or nine logical constants [Russell] |
18722 | Negations are not just reversals of truth-value, since that can happen without negation [Wittgenstein on Russell] |
14104 | Constants are absolutely definite and unambiguous [Russell] |
14114 | Variables don't stand alone, but exist as parts of propositional functions [Russell] |
14137 | 'Any' is better than 'all' where infinite classes are concerned [Russell] |
14149 | The Achilles Paradox concerns the one-one correlation of infinite classes [Russell] |
15895 | Russell discovered the paradox suggested by Burali-Forti's work [Russell, by Lavine] |
14152 | In geometry, Kant and idealists aimed at the certainty of the premisses [Russell] |
14154 | Geometry throws no light on the nature of actual space [Russell] |
14151 | Pure geometry is deductive, and neutral over what exists [Russell] |
14153 | In geometry, empiricists aimed at premisses consistent with experience [Russell] |
14155 | Two points have a line joining them (descriptive), a distance (metrical), and a whole line (projective) [Russell, by PG] |
18254 | Russell's approach had to treat real 5/8 as different from rational 5/8 [Russell, by Dummett] |
14144 | Ordinals result from likeness among relations, as cardinals from similarity among classes [Russell] |
14128 | Some claim priority for the ordinals over cardinals, but there is no logical priority between them [Russell] |
14129 | Ordinals presuppose two relations, where cardinals only presuppose one [Russell] |
14132 | Properties of numbers don't rely on progressions, so cardinals may be more basic [Russell] |
14141 | Ordinals are defined through mathematical induction [Russell] |
14142 | Ordinals are types of series of terms in a row, rather than the 'nth' instance [Russell] |
14139 | Transfinite ordinals don't obey commutativity, so their arithmetic is quite different from basic arithmetic [Russell] |
14145 | For Cantor ordinals are types of order, not numbers [Russell] |
14146 | We aren't sure if one cardinal number is always bigger than another [Russell] |
14135 | Real numbers are a class of rational numbers (and so not really numbers at all) [Russell] |
14123 | Some quantities can't be measured, and some non-quantities are measurable [Russell] |
14158 | Quantity is not part of mathematics, where it is replaced by order [Russell] |
14120 | Counting explains none of the real problems about the foundations of arithmetic [Russell] |
14118 | We can define one-to-one without mentioning unity [Russell] |
14119 | We do not currently know whether, of two infinite numbers, one must be greater than the other [Russell] |
14133 | There are cardinal and ordinal theories of infinity (while continuity is entirely ordinal) [Russell] |
14134 | Infinite numbers are distinguished by disobeying induction, and the part equalling the whole [Russell] |
14143 | ω names the whole series, or the generating relation of the series of ordinal numbers [Russell] |
14138 | You can't get a new transfinite cardinal from an old one just by adding finite numbers to it [Russell] |
14140 | For every transfinite cardinal there is an infinite collection of transfinite ordinals [Russell] |
14124 | Axiom of Archimedes: a finite multiple of a lesser magnitude can always exceed a greater [Russell] |
7530 | Russell tried to replace Peano's Postulates with the simple idea of 'class' [Russell, by Monk] |
18246 | Dedekind failed to distinguish the numbers from other progressions [Shapiro on Russell] |
14147 | Denying mathematical induction gave us the transfinite [Russell] |
14125 | Finite numbers, unlike infinite numbers, obey mathematical induction [Russell] |
14116 | Numbers were once defined on the basis of 1, but neglected infinities and + [Russell] |
14117 | Numbers are properties of classes [Russell] |
9977 | Ordinals can't be defined just by progression; they have intrinsic qualities [Russell] |
14162 | Mathematics doesn't care whether its entities exist [Russell] |
14103 | Pure mathematics is the class of propositions of the form 'p implies q' [Russell] |
21555 | For 'x is a u' to be meaningful, u must be one range of individuals (or 'type') higher than x [Russell] |
18003 | In 'x is a u', x and u must be of different types, so 'x is an x' is generally meaningless [Russell, by Magidor] |
11010 | Being is what belongs to every possible object of thought [Russell] |
14161 | Many things have being (as topics of propositions), but may not have actual existence [Russell] |
22919 | A thing which makes no difference seems unlikely to exist [Le Poidevin] |
14173 | What exists has causal relations, but non-existent things may also have them [Russell] |
14163 | Four classes of terms: instants, points, terms at instants only, and terms at instants and points [Russell] |
21341 | Philosophers of logic and maths insisted that a vocabulary of relations was essential [Russell, by Heil] |
18336 | Internal relations depend either on the existence of the relata, or on their properties [Rami] |
10586 | 'Reflexiveness' holds between a term and itself, and cannot be inferred from symmetry and transitiveness [Russell] |
10585 | Symmetrical and transitive relations are formally like equality [Russell] |
7781 | I call an object of thought a 'term'. This is a wide concept implying unity and existence. [Russell] |
14166 | Unities are only in propositions or concepts, and nothing that exists has unity [Russell] |
14164 | The only unities are simples, or wholes composed of parts [Russell] |
14112 | A set has some sort of unity, but not enough to be a 'whole' [Russell] |
14170 | Change is obscured by substance, a thing's nature, subject-predicate form, and by essences [Russell] |
14107 | Terms are identical if they belong to all the same classes [Russell] |
11849 | It at least makes sense to say two objects have all their properties in common [Wittgenstein on Russell] |
22303 | It makes no sense to say that a true proposition could have been false [Russell] |
22926 | In addition to causal explanations, they can also be inferential, or definitional, or purposive [Le Poidevin] |
10583 | Abstraction principles identify a common property, which is some third term with the right relation [Russell] |
10582 | The principle of Abstraction says a symmetrical, transitive relation analyses into an identity [Russell] |
10584 | A certain type of property occurs if and only if there is an equivalence relation [Russell] |
22932 | We don't just describe a time as 'now' from a private viewpoint, but as a fact about the world [Le Poidevin] |
14110 | Proposition contain entities indicated by words, rather than the words themselves [Russell] |
19164 | If propositions are facts, then false and true propositions are indistinguishable [Davidson on Russell] |
14111 | A proposition is a unity, and analysis destroys it [Russell] |
19157 | Russell said the proposition must explain its own unity - or else objective truth is impossible [Russell, by Davidson] |
22927 | The logical properties of causation are asymmetry, transitivity and irreflexivity [Le Poidevin] |
14175 | We can drop 'cause', and just make inferences between facts [Russell] |
14172 | Moments and points seem to imply other moments and points, but don't cause them [Russell] |
14174 | The laws of motion and gravitation are just parts of the definition of a kind of matter [Russell] |
14168 | Occupying a place and change are prior to motion, so motion is just occupying places at continuous times [Russell] |
14171 | Force is supposed to cause acceleration, but acceleration is a mathematical fiction [Russell] |
22922 | We can identify unoccupied points in space, so they must exist [Le Poidevin] |
22924 | If spatial points exist, then they must be stationary, by definition [Le Poidevin] |
14160 | Space is the extension of 'point', and aggregates of points seem necessary for geometry [Russell] |
22923 | Absolute space explains actual and potential positions, and geometrical truths [Le Poidevin] |
22928 | For relationists moving an object beyond the edge of space creates new space [Le Poidevin] |
22931 | We distinguish time from space, because it passes, and it has a unique present moment [Le Poidevin] |
22917 | Since nothing occurs in a temporal vacuum, there is no way to measure its length [Le Poidevin] |
22921 | Temporal vacuums would be unexperienced, unmeasured, and unending [Le Poidevin] |
22934 | Time can't speed up or slow down, so it doesn't seem to be a 'process' [Le Poidevin] |
22938 | To say that the past causes the present needs them both to be equally real [Le Poidevin] |
22939 | The B-series doesn't seem to allow change [Le Poidevin] |
22940 | If the B-universe is eternal, why am I trapped in a changing moment of it? [Le Poidevin] |
22947 | An ordered series can be undirected, but time favours moving from earlier to later [Le Poidevin] |
22952 | If time's arrow is causal, how can there be non-simultaneous events that are causally unconnected? [Le Poidevin] |
22951 | If time's arrow is psychological then different minds can impose different orders on events [Le Poidevin] |
22948 | There are Thermodynamic, Psychological and Causal arrows of time [Le Poidevin] |
22949 | Presumably if time's arrow is thermodynamic then time ends when entropy is complete [Le Poidevin] |
22950 | If time is thermodynamic then entropy is necessary - but the theory says it is probable [Le Poidevin] |
22953 | Time's arrow is not causal if there is no temporal gap between cause and effect [Le Poidevin] |
22943 | Instantaneous motion is an intrinsic disposition to be elsewhere [Le Poidevin] |
22945 | The dynamic view of motion says it is primitive, and not reducible to objects, properties and times [Le Poidevin] |
22937 | If the present could have diverse pasts, then past truths can't have present truthmakers [Le Poidevin] |
22925 | The present is the past/future boundary, so the first moment of time was not present [Le Poidevin] |
14156 | Mathematicians don't distinguish between instants of time and points on a line [Russell] |
22944 | The primitive parts of time are intervals, not instants [Le Poidevin] |
22942 | If time is infinitely divisible, then the present must be infinitely short [Le Poidevin] |
14169 | The 'universe' can mean what exists now, what always has or will exist [Russell] |
22946 | The multiverse is distinct time-series, as well as spaces [Le Poidevin] |
22941 | How could a timeless God know what time it is? So could God be both timeless and omniscient? [Le Poidevin] |