21 ideas
| 13838 | A decent modern definition should always imply a semantics [Hacking] |
| 5784 | In its primary and formal sense, 'true' applies to propositions, not beliefs [Russell] |
| 5777 | The truth or falsehood of a belief depends upon a fact to which the belief 'refers' [Russell] |
| 5783 | Propositions of existence, generalities, disjunctions and hypotheticals make correspondence tricky [Russell] |
| 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] |
| 13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [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] |
| 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] |
| 5780 | The three questions about belief are its contents, its success, and its character [Russell] |
| 5778 | If we object to all data which is 'introspective' we will cease to believe in toothaches [Russell] |
| 5779 | There are distinct sets of psychological and physical causal laws [Russell] |
| 5781 | Our important beliefs all, if put into words, take the form of propositions [Russell] |
| 5782 | A proposition expressed in words is a 'word-proposition', and one of images an 'image-proposition' [Russell] |
| 5776 | A proposition is what we believe when we believe truly or falsely [Russell] |
| 19068 | Causation interests us because we want to explain change [Mumford] |