19 ideas
| 6021 | It is only when we say a proposition that we speak truly or falsely [Sext.Empiricus] |
| 14249 | Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley] |
| 10830 | Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos] |
| 10829 | A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos] |
| 6020 | 'Man is a rational mortal animal' is equivalent to 'if something is a man, that thing is a rational mortal animal' [Sext.Empiricus] |
| 10832 | '∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos] |
| 10834 | Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos] |
| 13841 | Why should compactness be definitive of logic? [Boolos, by Hacking] |
| 10833 | Many concepts can only be expressed by second-order logic [Boolos] |
| 6026 | How can you investigate without some preconception of your object? [Sext.Empiricus] |
| 5662 | Maybe induction could never prove the existence of something unobservable [Ayer] |
| 5664 | Consciousness must involve a subject, and only bodies identify subjects [Ayer] |
| 5668 | People own conscious states because they are causally related to the identifying body [Ayer] |
| 5661 | We identify experiences by their owners, so we can't define owners by their experiences [Ayer] |
| 5665 | Memory is the best proposal as what unites bundles of experiences [Ayer] |
| 5666 | Not all exerience can be remembered, as this would produce an infinite regress [Ayer] |
| 5669 | Personal identity can't just be relations of experiences, because the body is needed to identify them [Ayer] |
| 6032 | Right actions, once done, are those with a reasonable justification [Sext.Empiricus] |
| 1517 | The tektraktys (1+2+3+4=10) is the 'fount of ever-flowing nature' [Sext.Empiricus] |