8 ideas
| 21552 | Common speech is vague; its vocabulary and syntax must be modified, for precision [Russell] |
| 21551 | Empirical words need ostensive definition, which makes them egocentric [Russell] |
| 13768 | Validity can preserve certainty in mathematics, but conditionals about contingents are another matter [Edgington] |
| 13770 | There are many different conditional mental states, and different conditional speech acts [Edgington] |
| 13764 | Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington] |
| 13765 | 'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington] |
| 20921 | How can we state relativism of sweet and sour, if they have no determinate nature? [Theophrastus] |
| 21550 | Science reduces indexicals to a minimum, but they can never be eliminated from empirical matters [Russell] |