23 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] |
14979 | Being alone doesn't guarantee intrinsic properties; 'being alone' is itself extrinsic [Lewis, by Sider] |
15454 | Extrinsic properties come in degrees, with 'brother' less extrinsic than 'sibling' [Lewis] |
15455 | Total intrinsic properties give us what a thing is [Lewis] |
8088 | People still say the Hopi have no time concepts, despite Whorf's later denial [Devlin] |
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] |
8122 | True works of art transmit completely new feelings [Tolstoy] |
8121 | Art is when one man uses external signs to hand on his feelings to another man [Tolstoy] |
8124 | The highest feelings of mankind can only be transmitted by art [Tolstoy] |
8123 | The purpose of art is to help mankind to evolve better, more socially beneficial feelings [Tolstoy] |
22710 | People estimate art according to their moral values [Tolstoy] |
8125 | The upper classes put beauty first, and thus freed themselves from morality [Tolstoy] |
8064 | We separate the concept of beauty from goodness, unlike the ancients [Tolstoy] |