91 ideas
| 12865 | Analytic philosophers may prefer formal systems because natural language is such mess [Simons] |
| 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] |
| 12815 | Classical mereology doesn't apply well to the objects around us [Simons] |
| 12832 | Complement: the rest of the Universe apart from some individual, written x-bar [Simons] |
| 12834 | Criticisms of mereology: parts? transitivity? sums? identity? four-dimensional? [Simons] |
| 12819 | A 'part' has different meanings for individuals, classes, and masses [Simons] |
| 12822 | Proper or improper part: x < y, 'x is (a) part of y' [Simons] |
| 12824 | Disjoint: two individuals are disjoint iff they do not overlap, written 'x | y' [Simons] |
| 12827 | Difference: the difference of individuals is the remainder of an overlap, written 'x - y' [Simons] |
| 12823 | Overlap: two parts overlap iff they have a part in common, expressed as 'x o y' [Simons] |
| 12825 | Product: the product of two individuals is the sum of all of their overlaps, written 'x · y' [Simons] |
| 12826 | Sum: the sum of individuals is what is overlapped if either of them are, written 'x + y' [Simons] |
| 12828 | General sum: the sum of objects satisfying some predicate, written σx(Fx) [Simons] |
| 12829 | General product: the nucleus of all objects satisfying a predicate, written πx(Fx) [Simons] |
| 12830 | Universe: the mereological sum of all objects whatever, written 'U' [Simons] |
| 12831 | Atom: an individual with no proper parts, written 'At x' [Simons] |
| 12844 | Dissective: stuff is dissective if parts of the stuff are always the stuff [Simons] |
| 12813 | Two standard formalisations of part-whole theory are the Calculus of Individuals, and Mereology [Simons] |
| 12821 | The part-relation is transitive and asymmetric (and thus irreflexive) [Simons] |
| 18847 | Each wheel is part of a car, but the four wheels are not a further part [Simons] |
| 12816 | Classical mereology doesn't handle temporal or modal notions very well [Simons] |
| 12846 | A 'group' is a collection with a condition which constitutes their being united [Simons] |
| 12848 | The same members may form two groups [Simons] |
| 12861 | 'The wolves' are the matter of 'the pack'; the latter is a group, with different identity conditions [Simons] |
| 12876 | Philosophy is stuck on the Fregean view that an individual is anything with a proper name [Simons] |
| 12845 | Some natural languages don't distinguish between singular and plural [Simons] |
| 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] |
| 12838 | Four-dimensional ontology has no change, since that needs an object, and time to pass [Simons] |
| 12842 | There are real relational changes, as well as bogus 'Cambridge changes' [Simons] |
| 12841 | I don't believe in processes [Simons] |
| 12836 | Fans of process ontology cheat, since river-stages refer to 'rivers' [Simons] |
| 12880 | Moments are things like smiles or skids, which are founded on other things [Simons] |
| 12881 | A smiling is an event with causes, but the smile is a continuant without causes [Simons] |
| 12882 | A wave is maintained by a process, but it isn't a process [Simons] |
| 12883 | Moving disturbances are are moments which continuously change their basis [Simons] |
| 12840 | I do not think there is a general identity condition for events [Simons] |
| 12839 | Relativity has an ontology of things and events, not on space-time diagrams [Simons] |
| 12879 | Independent objects can exist apart, and maybe even entirely alone [Simons] |
| 12847 | Mass nouns admit 'much' and 'a little', and resist 'many' and 'few'. [Simons] |
| 12863 | Mass terms (unlike plurals) are used with indifference to whether they can exist in units [Simons] |
| 12862 | Gold is not its atoms, because the atoms must be all gold, but gold contains neutrons [Simons] |
| 12859 | A mixture can have different qualities from its ingredients. [Simons] |
| 12858 | Mixtures disappear if nearly all of the mixture is one ingredient [Simons] |
| 15785 | Our commitments are to an 'ontology', but also to an 'ideology', or conceptual system [Hintikka] |
| 12850 | To individuate something we must pick it out, but also know its limits of variation [Simons] |
| 12860 | Sortal nouns for continuants tell you their continuance- and cessation-conditions [Simons] |
| 12886 | A whole requires some unique relation which binds together all of the parts [Simons] |
| 12857 | Tibbles isn't Tib-plus-tail, because Tibbles can survive its loss, but the sum can't [Simons] |
| 12835 | Does Tibbles remain the same cat when it loses its tail? [Simons] |
| 12820 | Without extensional mereology two objects can occupy the same position [Simons] |
| 12866 | Composition is asymmetric and transitive [Simons] |
| 12867 | A hand constitutes a fist (when clenched), but a fist is not composed of an augmented hand [Simons] |
| 12864 | We say 'b is part of a', 'b is a part of a', 'b are a part of a', or 'b are parts of a'. [Simons] |
| 12814 | Classical mereology says there are 'sums', for whose existence there is no other evidence [Simons] |
| 12817 | 'Mereological extensionality' says objects with the same parts are identical [Simons] |
| 12833 | If there are c atoms, this gives 2^c - 1 individuals, so there can't be just 2 or 12 individuals [Simons] |
| 12849 | Sums are more plausible for pluralities and masses than they are for individuals [Simons] |
| 12877 | Sums of things in different categories are found within philosophy. [Simons] |
| 12888 | The wholeness of a melody seems conventional, but of an explosion it seems natural [Simons] |
| 12871 | Objects have their essential properties because of the kind of objects they are [Simons] |
| 12870 | We must distinguish the de dicto 'must' of propositions from the de re 'must' of essence [Simons] |
| 12873 | Original parts are the best candidates for being essential to artefacts [Simons] |
| 12874 | An essential part of an essential part is an essential part of the whole [Simons] |
| 12837 | Four dimensional-objects are stranger than most people think [Simons] |
| 12856 | Intermittent objects would be respectable if they occurred in nature, as well as in artefacts [Simons] |
| 12885 | Objects like chess games, with gaps in them, are thereby less unified [Simons] |
| 12854 | An entrepreneur and a museum curator would each be happy with their ship at the end [Simons] |
| 12855 | The 'best candidate' theories mistakenly assume there is one answer to 'Which is the real ship?' [Simons] |
| 12872 | The zygote is an essential initial part, for a sexually reproduced organism [Simons] |
| 15786 | Commitment to possible worlds is part of our ideology, not part of our ontology [Hintikka] |
| 12889 | The limits of change for an individual depend on the kind of individual [Simons] |
| 12843 | With activities if you are doing it you've done it, with performances you must finish to have done it [Simons] |
| 12875 | One false note doesn't make it a performance of a different work [Simons] |