42 ideas
1597 | Thales was the first western thinker to believe the arché was intelligible [Roochnik on Thales] |
13939 | No possible evidence could decide the reality of numbers, so it is a pseudo-question [Carnap] |
16252 | Metaphysics uses empty words, or just produces pseudo-statements [Carnap] |
5750 | Consistency is modal, saying propositions are consistent if they could be true together [Melia] |
5737 | Predicate logic has connectives, quantifiers, variables, predicates, equality, names and brackets [Melia] |
5744 | First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious) [Melia] |
13342 | Carnap defined consequence by contradiction, but this is unintuitive and changes with substitution [Tarski on Carnap] |
13251 | Each person is free to build their own logic, just by specifying a syntax [Carnap] |
5740 | Second-order logic needs second-order variables and quantification into predicate position [Melia] |
5741 | If every model that makes premises true also makes conclusion true, the argument is valid [Melia] |
13936 | Questions about numbers are answered by analysis, and are analytic, and hence logically true [Carnap] |
8748 | Logical positivists incorporated geometry into logicism, saying axioms are just definitions [Carnap, by Shapiro] |
8960 | Internal questions about abstractions are trivial, and external ones deeply problematic [Carnap, by Szabó] |
13933 | Existence questions are 'internal' (within a framework) or 'external' (concerning the whole framework) [Carnap] |
13934 | To be 'real' is to be an element of a system, so we cannot ask reality questions about the system itself [Carnap] |
5735 | Maybe names and predicates can capture any fact [Melia] |
5736 | No sort of plain language or levels of logic can express modal facts properly [Melia] |
13938 | A linguistic framework involves commitment to entities, so only commitment to the framework is in question [Carnap] |
13935 | We only accept 'things' within a language with formation, testing and acceptance rules [Carnap] |
5746 | The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities [Melia] |
5738 | We may be sure that P is necessary, but is it necessarily necessary? [Melia] |
5732 | 'De re' modality is about things themselves, 'de dicto' modality is about propositions [Melia] |
5739 | Sometimes we want to specify in what ways a thing is possible [Melia] |
14305 | In the truth-functional account a burnt-up match was soluble because it never entered water [Carnap] |
3013 | Nothing is stronger than necessity, which rules everything [Thales, by Diog. Laertius] |
5734 | Possible worlds make it possible to define necessity and counterfactuals without new primitives [Melia] |
5742 | In possible worlds semantics the modal operators are treated as quantifiers [Melia] |
5743 | If possible worlds semantics is not realist about possible worlds, logic becomes merely formal [Melia] |
5749 | Possible worlds could be real as mathematics, propositions, properties, or like books [Melia] |
5751 | The truth of propositions at possible worlds are implied by the world, just as in books [Melia] |
13932 | Empiricists tend to reject abstract entities, and to feel sympathy with nominalism [Carnap] |
13937 | New linguistic claims about entities are not true or false, but just expedient, fruitful or successful [Carnap] |
18699 | Carnap tried to define all scientific predicates in terms of primitive relations, using type theory [Carnap, by Button] |
13940 | All linguistic forms in science are merely judged by their efficiency as instruments [Carnap] |
13048 | Good explications are exact, fruitful, simple and similar to the explicandum [Carnap, by Salmon] |
12131 | All concepts can be derived from a few basics, making possible one science of everything [Carnap, by Brody] |
5748 | We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia] |
11968 | The intension of a sentence is the set of all possible worlds in which it is true [Carnap, by Kaplan] |
18285 | All translation loses some content (but language does not create reality) [Carnap] |
1494 | Thales said water is the first principle, perhaps from observing that food is moist [Thales, by Aristotle] |
1713 | Thales must have thought soul causes movement, since he thought magnets have soul [Thales, by Aristotle] |
1742 | Thales said the gods know our wrong thoughts as well as our evil actions [Thales, by Diog. Laertius] |