76 ideas
22611 | Metaphysics can criticise interpretations of science theories, and give good feedback [Ingthorsson] |
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] |
22609 | Philosophers accepted first-order logic, because they took science to be descriptive, not explanatory [Ingthorsson] |
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] |
10974 | Compactness is when any consequence of infinite propositions is the consequence of a finite subset [Read] |
10975 | Compactness does not deny that an inference can have infinitely many premisses [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] |
22629 | Basic processes are said to be either physical, or organic, or psychological [Ingthorsson] |
22633 | Indirect realists are cautious about the manifest image, and prefer the scientific image [Ingthorsson] |
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] |
22606 | Neo-Humeans say there are no substantial connections between anything [Ingthorsson] |
22631 | Properties are said to be categorical qualities or non-qualitative dispositions [Ingthorsson] |
22632 | Physics understands the charge of an electron as a power, not as a quality [Ingthorsson] |
22627 | Compound objects are processes, insofar as change is essential to them [Ingthorsson] |
22613 | Most materialist views postulate smallest indivisible components which are permanent [Ingthorsson] |
10995 | A haecceity is a set of individual properties, essential to each thing [Read] |
22612 | Endurance and perdurance just show the consequences of A or B series time [Ingthorsson] |
22625 | Science suggests causal aspects of the constitution and persistance of objects [Ingthorsson] |
22620 | If causation involves production, that needs persisting objects [Ingthorsson] |
11001 | Equating necessity with truth in every possible world is the S5 conception of necessity [Read] |
10992 | The point of conditionals is to show that one will accept modus ponens [Read] |
10989 | The standard view of conditionals is that they are truth-functional [Read] |
11017 | Some people even claim that conditionals do not express propositions [Read] |
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] |
22636 | Every philosophical theory must be true in some possible world, so the ontology is hopeless [Ingthorsson] |
22638 | Worlds may differ in various respects, but no overall similarity of worlds is implied [Ingthorsson] |
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] |
10998 | The mind abstracts ways things might be, which are nonetheless real [Read] |
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] |
22605 | Humeans describe the surface of causation, while powers accounts aim at deeper explanations [Ingthorsson] |
22607 | Time and space are not causal, but they determine natural phenomena [Ingthorsson] |
22608 | Casuation is the transmission of conserved quantities between causal processes [Ingthorsson] |
22621 | Causation as transfer only works for asymmetric interactions [Ingthorsson] |
22614 | Interventionist causal theory says it gets a reliable result whenever you manipulate it [Ingthorsson] |
22639 | Causal events are always reciprocal, and there is no distinction of action and reaction [Ingthorsson] |
22615 | One effect cannot act on a second effect in causation, because the second doesn't yet exist [Ingthorsson] |
22616 | Empiricists preferred events to objects as the relata, because they have observable motions [Ingthorsson] |
22617 | Science now says all actions are reciprocal, not unidirectional [Ingthorsson] |
22619 | Causes are not agents; the whole interaction is the cause, and the changed compound is the effect [Ingthorsson] |
22635 | People only accept the counterfactual when they know the underlying cause [Ingthorsson] |
22634 | Counterfactuals don't explain causation, but causation can explain counterfactuals [Ingthorsson] |
22637 | Counterfactual theories are false in possible worlds where causation is actual [Ingthorsson] |
22624 | A cause can fail to produce its normal effect, by prevention, pre-emption, finks or antidotes [Ingthorsson] |
22622 | Any process can go backwards or forwards in time without violating the basic laws of physics [Ingthorsson] |
22618 | In modern physics the first and second laws of motion (unlike the third) fail at extremes [Ingthorsson] |
22630 | If particles have decay rates, they can't really be elementary, in the sense of indivisible [Ingthorsson] |
22610 | It is difficult to handle presentism in first-order logic [Ingthorsson] |
16713 | Philosophers are the forefathers of heretics [Tertullian] |
6610 | I believe because it is absurd [Tertullian] |