57 ideas
| 12027 | There must be a plausible epistemological theory alongside any metaphysical theory [Forbes,G] |
| 4643 | The Principle of Sufficient Reason does not presuppose that all explanations will be causal explanations [Baggini /Fosl] |
| 4633 | You cannot rationally deny the principle of non-contradiction, because all reasoning requires it [Baggini /Fosl] |
| 4635 | Dialectic aims at unified truth, unlike analysis, which divides into parts [Baggini /Fosl] |
| 12005 | The symbol 'ι' forms definite descriptions; (ιx)F(x) says 'the x which is such that F(x)' [Forbes,G] |
| 4632 | 'Natural' systems of deduction are based on normal rational practice, rather than on axioms [Baggini /Fosl] |
| 4631 | In ideal circumstances, an axiom should be such that no rational agent could possibly object to its use [Baggini /Fosl] |
| 15375 | If terms change their designations in different states, they are functions from states to objects [Fitting] |
| 15376 | Intensional logic adds a second type of quantification, over intensional objects, or individual concepts [Fitting] |
| 15378 | Awareness logic adds the restriction of an awareness function to epistemic logic [Fitting] |
| 15379 | Justication logics make explicit the reasons for mathematical truth in proofs [Fitting] |
| 11026 | Classical logic is deliberately extensional, in order to model mathematics [Fitting] |
| 4638 | The principle of bivalence distorts reality, as when claiming that a person is or is not 'thin' [Baggini /Fosl] |
| 12010 | Is the meaning of 'and' given by its truth table, or by its introduction and elimination rules? [Forbes,G] |
| 11028 | λ-abstraction disambiguates the scope of modal operators [Fitting] |
| 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] |
| 4640 | If identity is based on 'true of X' instead of 'property of X' we get the Masked Man fallacy ('I know X but not Y') [Baggini /Fosl, by PG] |
| 4647 | 'I have the same car as you' is fine; 'I have the same fiancée as you' is not so good [Baggini /Fosl] |
| 4639 | Leibniz's Law is about the properties of objects; the Identity of Indiscernibles is about perception of objects [Baggini /Fosl] |
| 4646 | Is 'events have causes' analytic a priori, synthetic a posteriori, or synthetic a priori? [Baggini /Fosl] |
| 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] |
| 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] |
| 15377 | Definite descriptions pick out different objects in different possible worlds [Fitting] |
| 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] |
| 4645 | 'A priori' does not concern how you learn a proposition, but how you show whether it is true or false [Baggini /Fosl] |
| 4582 | Basic beliefs are self-evident, or sensual, or intuitive, or revealed, or guaranteed [Baggini /Fosl] |
| 4644 | A proposition such as 'some swans are purple' cannot be falsified, only verified [Baggini /Fosl] |
| 4584 | The problem of induction is how to justify our belief in the uniformity of nature [Baggini /Fosl] |
| 4583 | How can an argument be good induction, but poor deduction? [Baggini /Fosl] |
| 4634 | Abduction aims at simplicity, testability, coherence and comprehensiveness [Baggini /Fosl] |
| 4637 | To see if an explanation is the best, it is necessary to investigate the alternative explanations [Baggini /Fosl] |
| 4629 | Consistency is the cornerstone of rationality [Baggini /Fosl] |