29 ideas
6118 | Philosophy is logical analysis, followed by synthesis [Russell] |
6116 | A logical language would show up the fallacy of inferring reality from ordinary language [Russell] |
6117 | Philosophy should be built on science, to reduce error [Russell] |
12204 | The logic of metaphysical necessity is S5 [Rumfitt] |
6110 | Subject-predicate logic (and substance-attribute metaphysics) arise from Aryan languages [Russell] |
11211 | If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt] |
6107 | It is logic, not metaphysics, that is fundamental to philosophy [Russell] |
12195 | Soundness in argument varies with context, and may be achieved very informally indeed [Rumfitt] |
12199 | There is a modal element in consequence, in assessing reasoning from suppositions [Rumfitt] |
12201 | We reject deductions by bad consequence, so logical consequence can't be deduction [Rumfitt] |
12194 | Contradictions include 'This is red and not coloured', as well as the formal 'B and not-B' [Rumfitt] |
6115 | Vagueness, and simples being beyond experience, are obstacles to a logical language [Russell] |
11212 | The sense of a connective comes from primitively obvious rules of inference [Rumfitt] |
11210 | Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt] |
12198 | Geometrical axioms in logic are nowadays replaced by inference rules (which imply the logical truths) [Rumfitt] |
6109 | Some axioms may only become accepted when they lead to obvious conclusions [Russell] |
6108 | Maths can be deduced from logical axioms and the logic of relations [Russell] |
10968 | Russell gave up logical atomism because of negative, general and belief propositions [Russell, by Read] |
6113 | To mean facts we assert them; to mean simples we name them [Russell] |
6114 | 'Simples' are not experienced, but are inferred at the limits of analysis [Russell] |
21722 | Better to construct from what is known, than to infer what is unknown [Russell] |
6111 | As propositions can be put in subject-predicate form, we wrongly infer that facts have substance-quality form [Russell] |
14532 | A distinctive type of necessity is found in logical consequence [Rumfitt, by Hale/Hoffmann,A] |
12193 | Logical necessity is when 'necessarily A' implies 'not-A is contradictory' [Rumfitt] |
12200 | A logically necessary statement need not be a priori, as it could be unknowable [Rumfitt] |
12202 | Narrow non-modal logical necessity may be metaphysical, but real logical necessity is not [Rumfitt] |
12203 | If a world is a fully determinate way things could have been, can anyone consider such a thing? [Rumfitt] |
6112 | Meaning takes many different forms, depending on different logical types [Russell] |
11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |