31 ideas
| 9821 | A definition need not capture the sense of an expression - just get the reference right [Frege, by Dummett] |
| 16477 | Asserting not-p is saying p is false [Russell] |
| 9585 | Since every definition is an equation, one cannot define equality itself [Frege] |
| 16484 | There are four experiences that lead us to talk of 'some' things [Russell] |
| 16486 | The physical world doesn't need logic, but the mental world does [Russell] |
| 2947 | Questions wouldn't lead anywhere without the law of excluded middle [Russell] |
| 16479 | 'Or' expresses hesitation, in a dog at a crossroads, or birds risking grabbing crumbs [Russell] |
| 16480 | A disjunction expresses indecision [Russell] |
| 16483 | Disjunction may also arise in practice if there is imperfect memory. [Russell] |
| 16481 | 'Or' expresses a mental state, not something about the world [Russell] |
| 16487 | Maybe the 'or' used to describe mental states is not the 'or' of logic [Russell] |
| 16475 | A 'heterological' predicate can't be predicated of itself; so is 'heterological' heterological? Yes=no! [Russell] |
| 17446 | Counting rests on one-one correspondence, of numerals to objects [Frege] |
| 9582 | Husserl rests sameness of number on one-one correlation, forgetting the correlation with numbers themselves [Frege] |
| 9586 | In a number-statement, something is predicated of a concept [Frege] |
| 9580 | Our concepts recognise existing relations, they don't change them [Frege] |
| 9589 | Numbers are not real like the sea, but (crucially) they are still objective [Frege] |
| 9577 | The naïve view of number is that it is like a heap of things, or maybe a property of a heap [Frege] |
| 9578 | If objects are just presentation, we get increasing abstraction by ignoring their properties [Frege] |
| 16482 | All our knowledge (if verbal) is general, because all sentences contain general words [Russell] |
| 4758 | Naïve realism leads to physics, but physics then shows that naïve realism is false [Russell] |
| 16476 | For simple words, a single experience can show that they are true [Russell] |
| 16485 | Perception can't prove universal generalisations, so abandon them, or abandon empiricism? [Russell] |
| 9581 | Many people have the same thought, which is the component, not the private presentation [Frege] |
| 9579 | Disregarding properties of two cats still leaves different objects, but what is now the difference? [Frege] |
| 9587 | How do you find the right level of inattention; you eliminate too many or too few characteristics [Frege] |
| 9588 | Number-abstraction somehow makes things identical without changing them! [Frege] |
| 9583 | Psychological logicians are concerned with sense of words, but mathematicians study the reference [Frege] |
| 9584 | Identity baffles psychologists, since A and B must be presented differently to identify them [Frege] |
| 16478 | A mother cat is paralysed if equidistant between two needy kittens [Russell] |
| 7667 | There are two sides to men - the pleasantly social, and the violent and creative [Diderot, by Berlin] |