42 ideas
9136 | The paradox of analysis says that any conceptual analysis must be either trivial or false [Sorensen] |
9131 | Two long understandable sentences can have an unintelligible conjunction [Sorensen] |
9139 | If nothing exists, no truthmakers could make 'Nothing exists' true [Sorensen] |
9140 | Which toothbrush is the truthmaker for 'buy one, get one free'? [Sorensen] |
10859 | A set is 'well-ordered' if every subset has a first element [Clegg] |
10857 | Set theory made a closer study of infinity possible [Clegg] |
10864 | Any set can always generate a larger set - its powerset, of subsets [Clegg] |
10872 | Extensionality: Two sets are equal if and only if they have the same elements [Clegg] |
10875 | Pairing: For any two sets there exists a set to which they both belong [Clegg] |
10876 | Unions: There is a set of all the elements which belong to at least one set in a collection [Clegg] |
10878 | Infinity: There exists a set of the empty set and the successor of each element [Clegg] |
10877 | Powers: All the subsets of a given set form their own new powerset [Clegg] |
10879 | Choice: For every set a mechanism will choose one member of any non-empty subset [Clegg] |
10871 | Axiom of Existence: there exists at least one set [Clegg] |
10874 | Specification: a condition applied to a set will always produce a new set [Clegg] |
9119 | No attempt to deny bivalence has ever been accepted [Sorensen] |
9135 | We now see that generalizations use variables rather than abstract entities [Sorensen] |
9125 | Denying problems, or being romantically defeated by them, won't make them go away [Sorensen] |
9137 | Banning self-reference would outlaw 'This very sentence is in English' [Sorensen] |
10880 | Mathematics can be 'pure' (unapplied), 'real' (physically grounded); or 'applied' (just applicable) [Clegg] |
10861 | Beyond infinity cardinals and ordinals can come apart [Clegg] |
10860 | An ordinal number is defined by the set that comes before it [Clegg] |
10854 | Transcendental numbers can't be fitted to finite equations [Clegg] |
10858 | By adding an axis of imaginary numbers, we get the useful 'number plane' instead of number line [Clegg] |
10853 | Either lack of zero made early mathematics geometrical, or the geometrical approach made zero meaningless [Clegg] |
10866 | Cantor's account of infinities has the shaky foundation of irrational numbers [Clegg] |
10869 | The Continuum Hypothesis is independent of the axioms of set theory [Clegg] |
10862 | The 'continuum hypothesis' says aleph-one is the cardinality of the reals [Clegg] |
9116 | Vague words have hidden boundaries [Sorensen] |
9132 | An offer of 'free coffee or juice' could slowly shift from exclusive 'or' to inclusive 'or' [Sorensen] |
9128 | It is propositional attitudes which can be a priori, not the propositions themselves [Sorensen] |
9130 | Attributing apriority to a proposition is attributing a cognitive ability to someone [Sorensen] |
9118 | The colour bands of the spectrum arise from our biology; they do not exist in the physics [Sorensen] |
9124 | We are unable to perceive a nose (on the back of a mask) as concave [Sorensen] |
9126 | Bayesians build near-certainty from lots of reasonably probable beliefs [Sorensen] |
9121 | Illusions are not a reason for skepticism, but a source of interesting scientific information [Sorensen] |
9134 | The negation of a meaningful sentence must itself be meaningful [Sorensen] |
9133 | Propositions are what settle problems of ambiguity in sentences [Sorensen] |
9129 | I can buy any litre of water, but not every litre of water [Sorensen] |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
9122 | God cannot experience unwanted pain, so God cannot understand human beings [Sorensen] |