38 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] |
17749 | Post proved the consistency of propositional logic in 1921 [Walicki] |
17765 | Propositional language can only relate statements as the same or as different [Walicki] |
17764 | Boolean connectives are interpreted as functions on the set {1,0} [Walicki] |
17752 | The empty set is useful for defining sets by properties, when the members are not yet known [Walicki] |
17753 | The empty set avoids having to take special precautions in case members vanish [Walicki] |
17759 | Ordinals play the central role in set theory, providing the model of well-ordering [Walicki] |
17741 | To determine the patterns in logic, one must identify its 'building blocks' [Walicki] |
17747 | A 'model' of a theory specifies interpreting a language in a domain to make all theorems true [Walicki] |
17748 | The L-S Theorem says no theory (even of reals) says more than a natural number theory [Walicki] |
17761 | A compact axiomatisation makes it possible to understand a field as a whole [Walicki] |
17763 | Axiomatic systems are purely syntactic, and do not presuppose any interpretation [Walicki] |
17758 | Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki] |
17755 | Ordinals are the empty set, union with the singleton, and any arbitrary union of ordinals [Walicki] |
17756 | The union of finite ordinals is the first 'limit ordinal'; 2ω is the second... [Walicki] |
17760 | Two infinite ordinals can represent a single infinite cardinal [Walicki] |
17757 | Members of ordinals are ordinals, and also subsets of ordinals [Walicki] |
17762 | In non-Euclidean geometry, all Euclidean theorems are valid that avoid the fifth postulate [Walicki] |
17754 | Inductive proof depends on the choice of the ordering [Walicki] |
17742 | Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki] |
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] |
6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |
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] |