24 ideas
8092 | Logic was merely a branch of rhetoric until the scientific 17th century [Devlin] |
4187 | 'There is nothing without a reason why it should be rather than not be' (a generalisation of 'Why?') [Schopenhauer] |
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] |
4192 | All necessity arises from causation, which is conditioned; there is no absolute or unconditioned necessity [Schopenhauer] |
4190 | All understanding is an immediate apprehension of the causal relation [Schopenhauer] |
8088 | People still say the Hopi have no time concepts, despite Whorf's later denial [Devlin] |
13195 | To explain a house we must describe its use, as well as its parts [Leibniz] |
13193 | Active force is not just potential for action, since it involves a real effort or striving [Leibniz] |
4191 | What we know in ourselves is not a knower but a will [Schopenhauer] |
21368 | The knot of the world is the use of 'I' to refer to both willing and knowing [Schopenhauer] |
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] |
13194 | God's laws would be meaningless without internal powers for following them [Leibniz] |
13196 | All qualities of bodies reduce to forces [Leibniz] |
13192 | Power is passive force, which is mass, and active force, which is entelechy or form [Leibniz] |
4189 | Time may be defined as the possibility of mutually exclusive conditions of the same thing [Schopenhauer] |