33 ideas
13838 | A decent modern definition should always imply a semantics [Hacking] |
18469 | God might necessitate that something happen, but He is not the truth-maker for it [Smith,B] |
8166 | Truth is part of semantics, since valid inference preserves truth [Dummett] |
13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking] |
13834 | Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking] |
13835 | Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking] |
13845 | The various logics are abstractions made from terms like 'if...then' in English [Hacking] |
13840 | First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking] |
13844 | A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking] |
13842 | Second-order completeness seems to need intensional entities and possible worlds [Hacking] |
8173 | Language can violate bivalence because of non-referring terms or ill-defined predicates [Dummett] |
8179 | The law of excluded middle is the logical reflection of the principle of bivalence [Dummett] |
13837 | With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking] |
13839 | Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking] |
13843 | If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking] |
8184 | Philosophers should not presume reality, but only invoke it when language requires it [Dummett] |
8185 | We can't make sense of a world not apprehended by a mind [Dummett] |
8163 | Since 'no bird here' and 'no squirrel here' seem the same, we must talk of 'atomic' facts [Dummett] |
8161 | We know we can state facts, with true statements [Dummett] |
8180 | 'That is red or orange' might be considered true, even though 'that is red' and 'that is orange' were not [Dummett] |
8178 | Empirical and a priori knowledge are not distinct, but are extremes of a sliding scale [Dummett] |
8175 | A theory of thought will include propositional attitudes as well as propositions [Dummett] |
8174 | The theories of meaning and understanding are the only routes to an account of thought [Dummett] |
8165 | To 'abstract from' is a logical process, as opposed to the old mental view [Dummett] |
8168 | To know the truth-conditions of a sentence, you must already know the meaning [Dummett] |
8181 | A justificationist theory of meaning leads to the rejection of classical logic [Dummett] |
8182 | Verificationism could be realist, if we imagined the verification by a superhuman power [Dummett] |
8183 | If truths about the past depend on memories and current evidence, the past will change [Dummett] |
8176 | We could only guess the meanings of 'true' and 'false' when sentences were used [Dummett] |
8170 | Sentences are the primary semantic units, because they can say something [Dummett] |
8169 | We can't distinguish a proposition from its content [Dummett] |
8186 | Time is the measure of change, so we can't speak of time before all change [Dummett] |
8167 | If Presentism is correct, we cannot even say that the present changes [Dummett] |