47 ideas
| 9921 | 'True' is only occasionally useful, as in 'everything Fermat believed was true' [Burgess/Rosen] |
| 13913 | The four 'perfect syllogisms' are called Barbara, Celarent, Darii and Ferio [Engelbretsen/Sayward] |
| 13914 | Syllogistic logic has one rule: what is affirmed/denied of wholes is affirmed/denied of their parts [Engelbretsen/Sayward] |
| 13915 | Syllogistic can't handle sentences with singular terms, or relational terms, or compound sentences [Engelbretsen/Sayward] |
| 13916 | Term logic uses expression letters and brackets, and '-' for negative terms, and '+' for compound terms [Engelbretsen/Sayward] |
| 9924 | Modal logic gives an account of metalogical possibility, not metaphysical possibility [Burgess/Rosen] |
| 9933 | The paradoxes are only a problem for Frege; Cantor didn't assume every condition determines a set [Burgess/Rosen] |
| 9928 | Mereology implies that acceptance of entities entails acceptance of conglomerates [Burgess/Rosen] |
| 13850 | In modern logic all formal validity can be characterised syntactically [Engelbretsen/Sayward] |
| 13849 | Classical logic rests on truth and models, where constructivist logic rests on defence and refutation [Engelbretsen/Sayward] |
| 13851 | Unlike most other signs, = cannot be eliminated [Engelbretsen/Sayward] |
| 9926 | A relation is either a set of sets of sets, or a set of sets [Burgess/Rosen] |
| 13852 | Axioms are ω-incomplete if the instances are all derivable, but the universal quantification isn't [Engelbretsen/Sayward] |
| 9932 | The paradoxes no longer seem crucial in critiques of set theory [Burgess/Rosen] |
| 9923 | We should talk about possible existence, rather than actual existence, of numbers [Burgess/Rosen] |
| 22886 | The modern idea of 'limit' allows infinite quantities to have a finite sum [Bardon] |
| 9925 | Structuralism and nominalism are normally rivals, but might work together [Burgess/Rosen] |
| 9934 | Number words became nouns around the time of Plato [Burgess/Rosen] |
| 22914 | An equally good question would be why there was nothing instead of something [Bardon] |
| 9918 | Abstract/concrete is a distinction of kind, not degree [Burgess/Rosen] |
| 9929 | Much of what science says about concrete entities is 'abstraction-laden' [Burgess/Rosen] |
| 9927 | Mathematics has ascended to higher and higher levels of abstraction [Burgess/Rosen] |
| 9930 | Abstraction is on a scale, of sets, to attributes, to type-formulas, to token-formulas [Burgess/Rosen] |
| 9919 | The old debate classified representations as abstract, not entities [Burgess/Rosen] |
| 22902 | Why does an effect require a prior event if the prior event isn't a cause? [Bardon] |
| 22905 | Becoming disordered is much easier for a system than becoming ordered [Bardon] |
| 9922 | If space is really just a force-field, then it is a physical entity [Burgess/Rosen] |
| 22913 | The universe expands, so space-time is enlarging [Bardon] |
| 22889 | We should treat time as adverbial, so we don't experience time, we experience things temporally [Bardon, by Bardon] |
| 22900 | How can we question the passage of time, if the question takes time to ask? [Bardon] |
| 22898 | What is time's passage relative to, and how fast does it pass? [Bardon] |
| 22897 | The A-series says a past event is becoming more past, but how can it do that? [Bardon] |
| 22901 | The B-series needs a revised view of causes, laws and explanations [Bardon] |
| 22896 | The B-series is realist about time, but idealist about its passage [Bardon] |
| 22903 | The B-series adds directionality when it accepts 'earlier' and 'later' [Bardon] |
| 22910 | To define time's arrow by causation, we need a timeless definition of causation [Bardon] |
| 22909 | We judge memories to be of the past because the events cause the memories [Bardon] |
| 22904 | The psychological arrow of time is the direction from our memories to our anticipations [Bardon] |
| 22906 | The direction of entropy is probabilistic, not necessary, so cannot be identical to time's arrow [Bardon] |
| 22907 | It is arbitrary to reverse time in a more orderly universe, but not in a sub-system of it [Bardon] |
| 22883 | It seems hard to understand change without understanding time first [Bardon] |
| 22890 | We experience static states (while walking round a house) and observe change (ship leaving dock) [Bardon] |
| 22884 | The motion of a thing should be a fact in the present moment [Bardon] |
| 22892 | Experiences of motion may be overlapping, thus stretching out the experience [Bardon] |
| 22911 | At least eternal time gives time travellers a possible destination [Bardon] |
| 22912 | Time travel is not a paradox if we include it in the eternal continuum of events [Bardon] |
| 22882 | We use calendars for the order of events, and clocks for their passing [Bardon] |