21 ideas
8092 | Logic was merely a branch of rhetoric until the scientific 17th century [Devlin] |
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] |
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] |
8072 | Sentences of apparent identical form can have different contextual meanings [Devlin] |
8075 | Space and time are atomic in the arrow, and divisible in the tortoise [Devlin] |
6417 | In 1921 Russell abandoned sense-data, and the gap between sensation and object [Russell, by Grayling] |
6474 | Seeing is not in itself knowledge, but is separate from what is seen, such as a patch of colour [Russell] |
6476 | We cannot assume that the subject actually exists, so we cannot distinguish sensations from sense-data [Russell] |
2792 | It is possible the world came into existence five minutes ago, complete with false memories [Russell] |
22326 | Knowledge needs more than a sensitive response; the response must also be appropriate [Russell] |
8088 | People still say the Hopi have no time concepts, despite Whorf's later denial [Devlin] |
6475 | In perception, the self is just a logical fiction demanded by grammar [Russell] |
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] |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |