53 ideas
6095 | The business of metaphysics is to describe the world [Russell] |
6106 | Reducing entities and premisses makes error less likely [Russell] |
6090 | Facts make propositions true or false, and are expressed by whole sentences [Russell] |
18348 | Not only atomic truths, but also general and negative truths, have truth-makers [Russell, by Rami] |
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] |
6103 | Normally a class with only one member is a problem, because the class and the member are identical [Russell] |
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] |
6092 | In a logically perfect language, there will be just one word for every simple object [Russell] |
6101 | Romulus does not occur in the proposition 'Romulus did not exist' [Russell] |
6102 | You can understand 'author of Waverley', but to understand 'Scott' you must know who it applies to [Russell] |
10423 | There are a set of criteria for pinning down a logically proper name [Russell, by Sainsbury] |
7744 | Treat description using quantifiers, and treat proper names as descriptions [Russell, by McCullogh] |
10426 | A name has got to name something or it is not a name [Russell] |
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] |
17763 | Axiomatic systems are purely syntactic, and do not presuppose any interpretation [Walicki] |
17761 | A compact axiomatisation makes it possible to understand a field as a whole [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] |
6104 | Numbers are classes of classes, and hence fictions of fictions [Russell] |
21708 | Russell's new logical atomist was of particulars, universals and facts (not platonic propositions) [Russell, by Linsky,B] |
19051 | Russell's atomic facts are actually compounds, and his true logical atoms are sense data [Russell, by Quine] |
6089 | Logical atomism aims at logical atoms as the last residue of analysis [Russell] |
6100 | Once you have enumerated all the atomic facts, there is a further fact that those are all the facts [Russell] |
6105 | Logical atoms aims to get down to ultimate simples, with their own unique reality [Russell] |
21709 | You can't name all the facts, so they are not real, but are what propositions assert [Russell] |
18376 | Russell asserts atomic, existential, negative and general facts [Russell, by Armstrong] |
5465 | Modern trope theory tries, like logical atomism, to reduce things to elementary states [Russell, by Ellis] |
6060 | 'Existence' means that a propositional function is sometimes true [Russell] |
17742 | Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki] |
6099 | Modal terms are properties of propositional functions, not of propositions [Russell] |
6098 | Perception goes straight to the fact, and not through the proposition [Russell] |
3158 | Theories of intentionality presuppose rationality, so can't explain it [Dennett] |
3159 | Beliefs and desires aren't real; they are prediction techniques [Dennett] |
6097 | The theory of error seems to need the existence of the non-existent [Russell] |
9022 | Russell uses 'propositional function' to refer to both predicates and to attributes [Quine on Russell] |
6091 | Propositions don't name facts, because each fact corresponds to a proposition and its negation [Russell] |
21702 | In 1918 still believes in nonlinguistic analogues of sentences, but he now calls them 'facts' [Russell, by Quine] |
6094 | An inventory of the world does not need to include propositions [Russell] |
6096 | I no longer believe in propositions, especially concerning falsehoods [Russell] |
21712 | I know longer believe in shadowy things like 'that today is Wednesday' when it is actually Tuesday [Russell] |
6093 | The names in a logically perfect language would be private, and could not be shared [Russell] |
6119 | You can discuss 'God exists', so 'God' is a description, not a name [Russell] |