25 ideas
8092 | Logic was merely a branch of rhetoric until the scientific 17th century [Devlin] |
15647 | Truth definitions don't produce a good theory, because they go beyond your current language [Halbach] |
15649 | In semantic theories of truth, the predicate is in an object-language, and the definition in a metalanguage [Halbach] |
15655 | Should axiomatic truth be 'conservative' - not proving anything apart from implications of the axioms? [Halbach] |
15654 | If truth is defined it can be eliminated, whereas axiomatic truth has various commitments [Halbach] |
15650 | Axiomatic theories of truth need a weak logical framework, and not a strong metatheory [Halbach] |
15648 | Instead of a truth definition, add a primitive truth predicate, and axioms for how it works [Halbach] |
15656 | Deflationists say truth merely serves to express infinite conjunctions [Halbach] |
8081 | 'No councillors are bankers' and 'All bankers are athletes' implies 'Some athletes are not councillors' [Devlin] |
8085 | Modern propositional inference replaces Aristotle's 19 syllogisms with modus ponens [Devlin] |
8086 | Predicate logic retains the axioms of propositional logic [Devlin] |
15657 | To prove the consistency of set theory, we must go beyond set theory [Halbach] |
8091 | Situation theory is logic that takes account of context [Devlin] |
8087 | Golden ages: 1900-1960 for pure logic, and 1950-1985 for applied logic [Devlin] |
8089 | Montague's intensional logic incorporated the notion of meaning [Devlin] |
8082 | Where a conditional is purely formal, an implication implies a link between premise and conclusion [Devlin] |
15652 | We can use truth instead of ontologically loaded second-order comprehension assumptions about properties [Halbach] |
8072 | Sentences of apparent identical form can have different contextual meanings [Devlin] |
15651 | Instead of saying x has a property, we can say a formula is true of x - as long as we have 'true' [Halbach] |
8075 | Space and time are atomic in the arrow, and divisible in the tortoise [Devlin] |
8088 | People still say the Hopi have no time concepts, despite Whorf's later denial [Devlin] |
22363 | You have only begun to do real science when you can express it in numbers [Kelvin] |
8073 | How do we parse 'time flies like an arrow' and 'fruit flies like an apple'? [Devlin] |
8076 | The distinction between sentences and abstract propositions is crucial in logic [Devlin] |
20644 | Energy has progressed from a mere formula, to a principle pervading all nature [Kelvin] |