42 ideas
21584 | A sense of timelessness is essential to wisdom [Russell] |
21572 | Philosophical disputes are mostly hopeless, because philosophers don't understand each other [Russell] |
21571 | Philosophical systems are interesting, but we now need a more objective scientific philosophy [Russell] |
21574 | Hegel's confusions over 'is' show how vast systems can be built on simple errors [Russell] |
21587 | Philosophers sometimes neglect truth and distort facts to attain a nice system [Russell] |
21582 | Physicists accept particles, points and instants, while pretending they don't do metaphysics [Russell] |
21573 | When problems are analysed properly, they are either logical, or not philosophical at all [Russell] |
18781 | Inconsistency doesn't prevent us reasoning about some system [Mares] |
18790 | Intuitionism as natural deduction has no rule for negation [Mares] |
18789 | Intuitionist logic looks best as natural deduction [Mares] |
18787 | Three-valued logic is useful for a theory of presupposition [Mares] |
21588 | Logic gives the method of research in philosophy [Russell] |
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] |
21586 | The logical connectives are not objects, but are formal, and need a context [Russell] |
18782 | The connectives are studied either through model theory or through proof theory [Mares] |
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] |
21585 | The tortoise won't win, because infinite instants don't compose an infinitely long time [Russell] |
18788 | For intuitionists there are not numbers and sets, but processes of counting and collecting [Mares] |
14664 | Necessary beings (numbers, properties, sets, propositions, states of affairs, God) exist in all possible worlds [Plantinga] |
21684 | Atomic facts may be inferrable from others, but never from non-atomic facts [Russell] |
22316 | A positive and negative fact have the same constituents; their difference is primitive [Russell] |
21576 | With asymmetrical relations (before/after) the reduction to properties is impossible [Russell] |
21575 | When we attribute a common quality to a group, we can forget the quality and just talk of the group [Russell] |
14666 | Socrates is a contingent being, but his essence is not; without Socrates, his essence is unexemplified [Plantinga] |
14662 | Possible worlds clarify possibility, propositions, properties, sets, counterfacts, time, determinism etc. [Plantinga] |
16472 | Plantinga's actualism is nominal, because he fills actuality with possibilia [Stalnaker on Plantinga] |
21580 | Science condemns sense-data and accepts matter, but a logical construction must link them [Russell] |
21583 | When sense-data change, there must be indistinguishable sense-data in the process [Russell] |
21577 | Empirical truths are particular, so general truths need an a priori input of generality [Russell] |
21579 | Objects are treated as real when they connect with other experiences in a normal way [Russell] |
21578 | Global scepticism is irrefutable, but can't replace our other beliefs, and just makes us hesitate [Russell] |
6416 | Other minds seem to exist, because their testimony supports realism about the world [Russell, by Grayling] |
18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
16469 | Plantinga has domains of sets of essences, variables denoting essences, and predicates as functions [Plantinga, by Stalnaker] |
16470 | Plantinga's essences have their own properties - so will have essences, giving a hierarchy [Stalnaker on Plantinga] |
14663 | Are propositions and states of affairs two separate things, or only one? I incline to say one [Plantinga] |
21581 | We never experience times, but only succession of events [Russell] |