65 ideas
| 12585 | Most people can't even define a chair [Peacocke] |
| 5515 | Imaginary cases are good for revealing our beliefs, rather than the truth [Parfit] |
| 13252 | Some truths have true negations [Beall/Restall] |
| 13247 | A truthmaker is an object which entails a sentence [Beall/Restall] |
| 10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
| 13249 | (∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically [Beall/Restall] |
| 13243 | Excluded middle must be true for some situation, not for all situations [Beall/Restall] |
| 13242 | It's 'relevantly' valid if all those situations make it true [Beall/Restall] |
| 13246 | Relevant logic does not abandon classical logic [Beall/Restall] |
| 13245 | Relevant consequence says invalidity is the conclusion not being 'in' the premises [Beall/Restall] |
| 13254 | A doesn't imply A - that would be circular [Beall/Restall] |
| 13255 | Relevant logic may reject transitivity [Beall/Restall] |
| 13250 | Free logic terms aren't existential; classical is non-empty, with referring names [Beall/Restall] |
| 13235 | Logic studies consequence; logical truths are consequences of everything, or nothing [Beall/Restall] |
| 13238 | Syllogisms are only logic when they use variables, and not concrete terms [Beall/Restall] |
| 13234 | The view of logic as knowing a body of truths looks out-of-date [Beall/Restall] |
| 10690 | Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall] |
| 13232 | Logic studies arguments, not formal languages; this involves interpretations [Beall/Restall] |
| 13241 | The model theory of classical predicate logic is mathematics [Beall/Restall] |
| 10691 | Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall] |
| 13253 | There are several different consequence relations [Beall/Restall] |
| 13240 | A sentence follows from others if they always model it [Beall/Restall] |
| 10695 | Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall] |
| 10689 | A step is a 'material consequence' if we need contents as well as form [Beall/Restall] |
| 10696 | A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall] |
| 13236 | Logical truth is much more important if mathematics rests on it, as logicism claims [Beall/Restall] |
| 10693 | Models are mathematical structures which interpret the non-logical primitives [Beall/Restall] |
| 13237 | Preface Paradox affirms and denies the conjunction of propositions in the book [Beall/Restall] |
| 10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
| 5516 | Reduction can be by identity, or constitution, or elimination [Parfit, by PG] |
| 13244 | Relevant necessity is always true for some situation (not all situations) [Beall/Restall] |
| 12581 | Perceptual concepts causally influence the content of our experiences [Peacocke] |
| 12579 | Perception has proto-propositions, between immediate experience and concepts [Peacocke] |
| 12586 | Consciousness of a belief isn't a belief that one has it [Peacocke] |
| 3539 | Personal identity is just causally related mental states [Parfit, by Maslin] |
| 5514 | Psychologists are interested in identity as a type of person, but philosophers study numerical identity [Parfit] |
| 1393 | One of my future selves will not necessarily be me [Parfit] |
| 5521 | If my brain-halves are transplanted into two bodies, I have continuity, and don't need identity [Parfit] |
| 5522 | Over a period of time what matters is not that 'I' persist, but that I have psychological continuity [Parfit] |
| 1392 | If we split like amoeba, we would be two people, neither of them being us [Parfit] |
| 5519 | It is fine to save two dying twins by merging parts of their bodies into one, and identity is irrelevant [Parfit] |
| 5520 | If two humans are merged surgically, the new identity is a purely verbal problem [Parfit] |
| 1391 | Concern for our own lives isn't the source of belief in identity, it is the result of it [Parfit] |
| 5518 | It doesn't matter whether I exist with half my components replaced (any more than an audio system) [Parfit] |
| 13239 | Judgement is always predicating a property of a subject [Beall/Restall] |
| 12608 | Concepts are distinguished by roles in judgement, and are thus tied to rationality [Peacocke] |
| 18568 | Philosophy should merely give necessary and sufficient conditions for concept possession [Peacocke, by Machery] |
| 18571 | Peacocke's account of possession of a concept depends on one view of counterfactuals [Peacocke, by Machery] |
| 18572 | Peacocke's account separates psychology from philosophy, and is very sketchy [Machery on Peacocke] |
| 17722 | The concept 'red' is tied to what actually individuates red things [Peacocke] |
| 11127 | If concepts just are mental representations, what of concepts we may never acquire? [Peacocke] |
| 12577 | Possessing a concept is being able to make judgements which use it [Peacocke] |
| 12578 | A concept is just what it is to possess that concept [Peacocke] |
| 12587 | Employing a concept isn't decided by introspection, but by making judgements using it [Peacocke] |
| 12605 | A sense is individuated by the conditions for reference [Peacocke] |
| 12607 | Fregean concepts have their essence fixed by reference-conditions [Peacocke] |
| 12609 | Concepts have distinctive reasons and norms [Peacocke] |
| 12584 | An analysis of concepts must link them to something unconceptualized [Peacocke] |
| 12604 | Any explanation of a concept must involve reference and truth [Peacocke] |
| 9335 | Concepts are constituted by their role in a group of propositions to which we are committed [Peacocke, by Greco] |
| 9336 | A concept's reference is what makes true the beliefs of its possession conditions [Peacocke, by Horwich] |
| 12610 | Encountering novel sentences shows conclusively that meaning must be compositional [Peacocke] |
| 13248 | We can rest truth-conditions on situations, rather than on possible worlds [Beall/Restall] |
| 13233 | Propositions commit to content, and not to any way of spelling it out [Beall/Restall] |
| 9762 | We should focus less on subjects of experience, and more on the experiences themselves [Parfit] |