34 ideas
14611 | Metaphysics should avoid talk of past, present or future [Smart] |
17070 | Coherence is consilience, simplicity, analogy, and fitting into a web of belief [Smart] |
17072 | We need comprehensiveness, as well as self-coherence [Smart] |
7786 | Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [Girle] |
7798 | There are three axiom schemas for propositional logic [Girle] |
7799 | Proposition logic has definitions for its three operators: or, and, and identical [Girle] |
7797 | Axiom systems of logic contain axioms, inference rules, and definitions of proof and theorems [Girle] |
7794 | There are seven modalities in S4, each with its negation [Girle] |
7793 | ◊p → □◊p is the hallmark of S5 [Girle] |
7795 | S5 has just six modalities, and all strings can be reduced to those [Girle] |
7787 | Possible worlds logics use true-in-a-world rather than true [Girle] |
7788 | Modal logic has four basic modal negation equivalences [Girle] |
7796 | Modal logics were studied in terms of axioms, but now possible worlds semantics is added [Girle] |
7789 | Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle] |
7790 | If an argument is invalid, a truth tree will indicate a counter-example [Girle] |
7800 | Analytic truths are divided into logically and conceptually necessary [Girle] |
7801 | Possibilities can be logical, theoretical, physical, economic or human [Girle] |
7792 | A world has 'access' to a world it generates, which is important in possible worlds semantics [Girle] |
17073 | I simply reject evidence, if it is totally contrary to my web of belief [Smart] |
17077 | The height of a flagpole could be fixed by its angle of shadow, but that would be very unusual [Smart] |
17078 | Universe expansion explains the red shift, but not vice versa [Smart] |
17061 | Explanation of a fact is fitting it into a system of beliefs [Smart] |
17074 | Explanations are bad by fitting badly with a web of beliefs, or fitting well into a bad web [Smart] |
17076 | Deducing from laws is one possible way to achieve a coherent explanation [Smart] |
17071 | An explanation is better if it also explains phenomena from a different field [Smart] |
17062 | If scientific explanation is causal, that rules out mathematical explanation [Smart] |
17075 | Scientific explanation tends to reduce things to the unfamiliar (not the familiar) [Smart] |
22405 | Negative utilitarianism implies that the world should be destroyed, to avoid future misery [Smart] |
22404 | Any group interested in ethics must surely have a sentiment of generalised benevolence [Smart] |
14613 | Special relativity won't determine a preferred frame, but we can pick one externally [Smart] |
17063 | Unlike Newton, Einstein's general theory explains the perihelion of Mercury [Smart] |
14615 | If time flows, then 'how fast does it flow?' is a tricky question [Smart] |
14614 | The past, present, future and tenses of A-theory are too weird, and should be analysed indexically [Smart] |
1513 | The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus] |