51 ideas
8092 | Logic was merely a branch of rhetoric until the scientific 17th century [Devlin] |
15879 | The Square of Opposition has two contradictory pairs, one contrary pair, and one sub-contrary pair [Harré] |
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] |
15891 | Traditional quantifiers combine ordinary language generality and ontology assumptions [Harré] |
15878 | Some quantifiers, such as 'any', rule out any notion of order within their range [Harré] |
8075 | Space and time are atomic in the arrow, and divisible in the tortoise [Devlin] |
15874 | Scientific properties are not observed qualities, but the dispositions which create them [Harré] |
15884 | Laws of nature remain the same through any conditions, if the underlying mechanisms are unchanged [Harré] |
8088 | People still say the Hopi have no time concepts, despite Whorf's later denial [Devlin] |
15880 | In physical sciences particular observations are ordered, but in biology only the classes are ordered [Harré] |
15869 | Reports of experiments eliminate the experimenter, and present results as the behaviour of nature [Harré] |
15881 | We can save laws from counter-instances by treating the latter as analytic definitions [Harré] |
15882 | Since there are three different dimensions for generalising laws, no one system of logic can cover them [Harré] |
15888 | The grue problem shows that natural kinds are central to science [Harré] |
15887 | 'Grue' introduces a new causal hypothesis - that emeralds can change colour [Harré] |
15889 | It is because ravens are birds that their species and their colour might be connected [Harré] |
15890 | Non-black non-ravens just aren't part of the presuppositions of 'all ravens are black' [Harré] |
15885 | The necessity of Newton's First Law derives from the nature of material things, not from a mechanism [Harré] |
15868 | Idealisation idealises all of a thing's properties, but abstraction leaves some of them out [Harré] |
20429 | Most of us are too close to our own motives to understand them [Fry] |
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] |
20424 | Imaginative life requires no action, so new kinds of perception and values emerge in art [Fry] |
20427 | Everyone reveals an aesthetic attitude, looking at something which only exists to be seen [Fry] |
20433 | 'Beauty' can either mean sensuous charm, or the aesthetic approval of art (which may be ugly) [Fry] |
20430 | In life we neglect 'cosmic emotion', but it matters, and art brings it to the fore [Fry] |
20431 | Art needs a mixture of order and variety in its sensations [Fry] |
20423 | If graphic arts only aim at imitation, their works are only trivial ingenious toys [Fry] |
20428 | Popular opinion favours realism, yet most people never look closely at anything! [Fry] |
20432 | When viewing art, rather than flowers, we are aware of purpose, and sympathy with its creator [Fry] |
20425 | In the cinema the emotions are weaker, but much clearer than in ordinary life [Fry] |
20426 | For pure moralists art must promote right action, and not just be harmless [Fry] |
15886 | Science rests on the principle that nature is a hierarchy of natural kinds [Harré] |
15864 | Classification is just as important as laws in natural science [Harré] |
15865 | Newton's First Law cannot be demonstrated experimentally, as that needs absence of external forces [Harré] |
15862 | Laws can come from data, from theory, from imagination and concepts, or from procedures [Harré] |
15870 | Are laws of nature about events, or types and universals, or dispositions, or all three? [Harré] |
15871 | Are laws about what has or might happen, or do they also cover all the possibilities? [Harré] |
15876 | Maybe laws of nature are just relations between properties? [Harré] |
15860 | We take it that only necessary happenings could be laws [Harré] |
15872 | Must laws of nature be universal, or could they be local? [Harré] |
15867 | Laws describe abstract idealisations, not the actual mess of nature [Harré] |
15892 | Laws of nature state necessary connections of things, events and properties, based on models of mechanisms [Harré] |
15875 | In counterfactuals we keep substances constant, and imagine new situations for them [Harré] |