71 ideas
6575 | Philosophy may never find foundations, and may undermine our lives in the process [Fogelin] |
6585 | Rationality is threatened by fear of inconsistency, illusions of absolutes or relativism, and doubt [Fogelin] |
6557 | Humans may never be able to attain a world view which is both rich and consistent [Fogelin] |
6568 | A game can be played, despite having inconsistent rules [Fogelin] |
6560 | The law of noncontradiction is traditionally the most basic principle of rationality [Fogelin] |
6565 | The law of noncontradiction makes the distinction between asserting something and denying it [Fogelin] |
6574 | Legal reasoning is analogical, not deductive [Fogelin] |
10987 | Three traditional names of rules are 'Simplification', 'Addition' and 'Disjunctive Syllogism' [Read] |
11004 | Necessity is provability in S4, and true in all worlds in S5 [Read] |
11018 | There are fuzzy predicates (and sets), and fuzzy quantifiers and modifiers [Read] |
11011 | Same say there are positive, negative and neuter free logics [Read] |
11020 | Realisms like the full Comprehension Principle, that all good concepts determine sets [Read] |
10986 | Not all validity is captured in first-order logic [Read] |
10972 | The non-emptiness of the domain is characteristic of classical logic [Read] |
11024 | Semantics must precede proof in higher-order logics, since they are incomplete [Read] |
10985 | We should exclude second-order logic, precisely because it captures arithmetic [Read] |
10970 | A theory of logical consequence is a conceptual analysis, and a set of validity techniques [Read] |
10984 | Logical consequence isn't just a matter of form; it depends on connections like round-square [Read] |
10973 | A theory is logically closed, which means infinite premisses [Read] |
11007 | Quantifiers are second-order predicates [Read] |
10978 | In second-order logic the higher-order variables range over all the properties of the objects [Read] |
10971 | A logical truth is the conclusion of a valid inference with no premisses [Read] |
10988 | Any first-order theory of sets is inadequate [Read] |
10975 | Compactness does not deny that an inference can have infinitely many premisses [Read] |
10974 | Compactness is when any consequence of infinite propositions is the consequence of a finite subset [Read] |
10977 | Compactness blocks the proof of 'for every n, A(n)' (as the proof would be infinite) [Read] |
10976 | Compactness makes consequence manageable, but restricts expressive power [Read] |
11014 | Self-reference paradoxes seem to arise only when falsity is involved [Read] |
11025 | Infinite cuts and successors seems to suggest an actual infinity there waiting for us [Read] |
10979 | Although second-order arithmetic is incomplete, it can fully model normal arithmetic [Read] |
10980 | Second-order arithmetic covers all properties, ensuring categoricity [Read] |
10997 | Von Neumann numbers are helpful, but don't correctly describe numbers [Read] |
8439 | Maybe each event has only one possible causal history [Bennett] |
8440 | Maybe an event's time of occurrence is essential to it [Bennett] |
11016 | Would a language without vagueness be usable at all? [Read] |
11019 | Supervaluations say there is a cut-off somewhere, but at no particular place [Read] |
11012 | A 'supervaluation' gives a proposition consistent truth-value for classical assignments [Read] |
11013 | Identities and the Indiscernibility of Identicals don't work with supervaluations [Read] |
10995 | A haecceity is a set of individual properties, essential to each thing [Read] |
11001 | Equating necessity with truth in every possible world is the S5 conception of necessity [Read] |
10989 | The standard view of conditionals is that they are truth-functional [Read] |
10992 | The point of conditionals is to show that one will accept modus ponens [Read] |
11017 | Some people even claim that conditionals do not express propositions [Read] |
6582 | Conventions can only work if they are based on something non-conventional [Fogelin] |
10983 | Knowledge of possible worlds is not causal, but is an ontology entailed by semantics [Read] |
10982 | How can modal Platonists know the truth of a modal proposition? [Read] |
10996 | Actualism is reductionist (to parts of actuality), or moderate realist (accepting real abstractions) [Read] |
10981 | A possible world is a determination of the truth-values of all propositions of a domain [Read] |
11000 | If worlds are concrete, objects can't be present in more than one, and can only have counterparts [Read] |
6576 | My view is 'circumspect rationalism' - that only our intellect can comprehend the world [Fogelin] |
6589 | Knowledge is legitimate only if all relevant defeaters have been eliminated [Fogelin] |
6596 | For coherentists, circularity is acceptable if the circle is large, rich and coherent [Fogelin] |
6597 | A rule of justification might be: don't raise the level of scrutiny without a good reason [Fogelin] |
6588 | Scepticism is cartesian (sceptical scenarios), or Humean (future), or Pyrrhonian (suspend belief) [Fogelin] |
6590 | Scepticism deals in remote possibilities that are ineliminable and set the standard very high [Fogelin] |
6583 | Radical perspectivism replaces Kant's necessary scheme with many different schemes [Fogelin] |
10998 | The mind abstracts ways things might be, which are nonetheless real [Read] |
6555 | We are also irrational, with a unique ability to believe in bizarre self-created fictions [Fogelin] |
11005 | Negative existentials with compositionality make the whole sentence meaningless [Read] |
10966 | A proposition objectifies what a sentence says, as indicative, with secure references [Read] |
6605 | Critics must be causally entangled with their subject matter [Fogelin] |
6607 | The word 'beautiful', when deprived of context, is nearly contentless [Fogelin] |
6604 | Saying 'It's all a matter to taste' ignores the properties of the object discussed [Fogelin] |
6586 | Cynics are committed to morality, but disappointed or disgusted by human failings [Fogelin] |
6572 | Deterrence, prevention, rehabilitation and retribution can come into conflict in punishments [Fogelin] |
6573 | Retributivists say a crime can be 'paid for'; deterrentists still worry about potential victims [Fogelin] |
8441 | Delaying a fire doesn't cause it, but hastening it might [Bennett] |
8436 | Either cause and effect are subsumed under a conditional because of properties, or it is counterfactual [Bennett] |
8435 | Causes are between events ('the explosion') or between facts/states of affairs ('a bomb dropped') [Bennett] |
8437 | The full counterfactual story asserts a series of events, because counterfactuals are not transitive [Bennett] |
8438 | A counterfactual about an event implies something about the event's essence [Bennett] |