20 ideas
20728 | Metaphysics is hopeless with its present epistemology; common-sense realism is needed [Colvin] |
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] |
20726 | We can only distinguish self from non-self if there is an inflexible external reality [Colvin] |
20727 | Common-sense realism rests on our interests and practical life [Colvin] |
20729 | Arguments that objects are unknowable or non-existent assume the knower's existence [Colvin] |
20730 | If objects are doubted because their appearances change, that presupposes one object [Colvin] |
20731 | The idea that everything is relations is contradictory; relations are part of the concept of things [Colvin] |
18528 | The single imagined 'interval' between things only exists in the intellect [Auriol] |
16589 | Prime matter lacks essence, but is only potentially and indeterminately a physical thing [Auriol] |
16651 | God can do anything non-contradictory, as making straightness with no line, or lightness with no parts [Auriol] |