60 ideas
| 12027 | There must be a plausible epistemological theory alongside any metaphysical theory [Forbes,G] |
| 17713 | After 1903, Husserl avoids metaphysical commitments [Mares] |
| 18781 | Inconsistency doesn't prevent us reasoning about some system [Mares] |
| 12005 | The symbol 'ι' forms definite descriptions; (ιx)F(x) says 'the x which is such that F(x)' [Forbes,G] |
| 18789 | Intuitionist logic looks best as natural deduction [Mares] |
| 18790 | Intuitionism as natural deduction has no rule for negation [Mares] |
| 18787 | Three-valued logic is useful for a theory of presupposition [Mares] |
| 10247 | We have no adequate logic at the moment, so mathematicians must create one [Veblen] |
| 18793 | Material implication (and classical logic) considers nothing but truth values for implications [Mares] |
| 18784 | In classical logic the connectives can be related elegantly, as in De Morgan's laws [Mares] |
| 18786 | Excluded middle standardly implies bivalence; attacks use non-contradiction, De M 3, or double negation [Mares] |
| 18780 | Standard disjunction and negation force us to accept the principle of bivalence [Mares] |
| 18782 | The connectives are studied either through model theory or through proof theory [Mares] |
| 12010 | Is the meaning of 'and' given by its truth table, or by its introduction and elimination rules? [Forbes,G] |
| 18783 | Many-valued logics lack a natural deduction system [Mares] |
| 18792 | Situation semantics for logics: not possible worlds, but information in situations [Mares] |
| 18785 | Consistency is semantic, but non-contradiction is syntactic [Mares] |
| 17715 | The truth of the axioms doesn't matter for pure mathematics, but it does for applied [Mares] |
| 17716 | Mathematics is relations between properties we abstract from experience [Mares] |
| 18788 | For intuitionists there are not numbers and sets, but processes of counting and collecting [Mares] |
| 12023 | Vagueness problems arise from applying sharp semantics to vague languages [Forbes,G] |
| 12017 | In all instances of identity, there must be some facts to ensure the identity [Forbes,G] |
| 12024 | If we combined two clocks, it seems that two clocks may have become one clock. [Forbes,G] |
| 11885 | Only individual essences will ground identities across worlds in other properties [Forbes,G, by Mackie,P] |
| 12014 | An individual essence is a set of essential properties which only that object can have [Forbes,G] |
| 12015 | Non-trivial individual essence is properties other than de dicto, or universal, or relational [Forbes,G] |
| 12013 | Essential properties depend on a category, and perhaps also on particular facts [Forbes,G] |
| 13804 | A property is essential iff the object would not exist if it lacked that property [Forbes,G] |
| 13805 | Properties are trivially essential if they are not grounded in a thing's specific nature [Forbes,G] |
| 12012 | Essential properties are those without which an object could not exist [Forbes,G] |
| 13808 | A relation is essential to two items if it holds in every world where they exist [Forbes,G] |
| 13806 | Trivially essential properties are existence, self-identity, and de dicto necessities [Forbes,G] |
| 13807 | A property is 'extraneously essential' if it is had only because of the properties of other objects [Forbes,G] |
| 12022 | Same parts does not ensure same artefact, if those parts could constitute a different artefact [Forbes,G] |
| 12025 | Artefacts have fuzzy essences [Forbes,G] |
| 13809 | One might be essentialist about the original bronze from which a statue was made [Forbes,G] |
| 12020 | An individual might change their sex in a world, but couldn't have differed in sex at origin [Forbes,G] |
| 11888 | Identities must hold because of other facts, which must be instrinsic [Forbes,G, by Mackie,P] |
| 12003 | De re modal formulae, unlike de dicto, are sensitive to transworld identities [Forbes,G] |
| 12028 | De re necessity is a form of conceptual necessity, just as de dicto necessity is [Forbes,G] |
| 13810 | The source of de dicto necessity is not concepts, but the actual properties of the thing [Forbes,G] |
| 17703 | Light in straight lines is contingent a priori; stipulated as straight, because they happen to be so [Mares] |
| 12008 | Unlike places and times, we cannot separate possible worlds from what is true at them [Forbes,G] |
| 12009 | The problem with possible worlds realism is epistemological; we can't know properties of possible objects [Forbes,G] |
| 12007 | Possible worlds are points of logical space, rather like other times than our own [Forbes,G] |
| 12011 | Transworld identity concerns the limits of possibility for ordinary things [Forbes,G] |
| 12016 | The problem of transworld identity can be solved by individual essences [Forbes,G] |
| 12004 | Counterpart theory is not good at handling the logic of identity [Forbes,G] |
| 12021 | Haecceitism attributes to each individual a primitive identity or thisness [Forbes,G] |
| 12029 | We believe in thisnesses, because we reject bizarre possibilities as not being about that individual [Forbes,G] |
| 17714 | Aristotelians dislike the idea of a priori judgements from pure reason [Mares] |
| 17705 | Empiricists say rationalists mistake imaginative powers for modal insights [Mares] |
| 17700 | The most popular view is that coherent beliefs explain one another [Mares] |
| 17704 | Operationalism defines concepts by our ways of measuring them [Mares] |
| 17710 | Aristotelian justification uses concepts abstracted from experience [Mares] |
| 17706 | The essence of a concept is either its definition or its conceptual relations? [Mares] |
| 18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
| 17701 | Possible worlds semantics has a nice compositional account of modal statements [Mares] |
| 17702 | Unstructured propositions are sets of possible worlds; structured ones have components [Mares] |
| 17708 | Maybe space has points, but processes always need regions with a size [Mares] |