32 ideas
| 13838 | A decent modern definition should always imply a semantics [Hacking] |
| 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] |
| 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] |
| 22427 | To explain object qualities, primary qualities must be more than mere sources of experience [McGinn] |
| 22413 | Being red simply consists in looking red [McGinn] |
| 22415 | Relativity means differing secondary perceptions are not real disagreements [McGinn] |
| 22416 | Phenomenalism is correct for secondary qualities, so scepticism is there impossible [McGinn] |
| 22422 | Maybe all possible sense experience must involve both secondary and primary qualities [McGinn] |
| 22428 | You understood being red if you know the experience involved; not so with thngs being square [McGinn] |
| 22414 | You don't need to know how a square thing looks or feels to understand squareness [McGinn] |
| 22423 | Touch doesn't provide direct experience of primary qualities, because touch feels temperature [McGinn] |
| 22426 | We can perceive objectively, because primary qualities are not mind-created [McGinn] |
| 22412 | Lockean secondary qualities (unlike primaries) produce particular sensory experiences [McGinn] |
| 22421 | Could there be a mind which lacked secondary quality perception? [McGinn] |
| 22424 | Secondary qualities contain information; their variety would be superfluous otherwise [McGinn] |
| 22425 | The utility theory says secondary qualities give information useful to human beings [McGinn] |
| 7629 | We see objects 'directly' by representing them [McGinn] |
| 22420 | The indexical perspective is subjective, incorrigible and constant [McGinn] |
| 18410 | Indexical thought is in relation to my self-consciousness [McGinn] |
| 22417 | Indexicals do not figure in theories of physics, because they are not explanatory causes [McGinn] |
| 18402 | Indexical concepts are indispensable, as we need them for the power to act [McGinn] |
| 22418 | I can know indexical truths a priori, unlike their non-indexical paraphrases [McGinn] |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |