20 ideas
| 7548 | Classes, grouped by a convenient property, are logical constructions [Russell] |
| 7545 | Visible things are physical and external, but only exist when viewed [Russell] |
| 3626 | Knowing the attributes is enough to reveal a substance [Descartes] |
| 3630 | Our thinking about external things doesn't disprove the existence of innate ideas [Descartes] |
| 6417 | In 1921 Russell abandoned sense-data, and the gap between sensation and object [Russell, by Grayling] |
| 6474 | Seeing is not in itself knowledge, but is separate from what is seen, such as a patch of colour [Russell] |
| 7549 | If my body literally lost its mind, the object seen when I see a flash would still exist [Russell] |
| 7553 | Sense-data are purely physical [Russell] |
| 6476 | We cannot assume that the subject actually exists, so we cannot distinguish sensations from sense-data [Russell] |
| 2792 | It is possible the world came into existence five minutes ago, complete with false memories [Russell] |
| 22326 | Knowledge needs more than a sensitive response; the response must also be appropriate [Russell] |
| 7546 | A man is a succession of momentary men, bound by continuity and causation [Russell] |
| 6475 | In perception, the self is just a logical fiction demanded by grammar [Russell] |
| 7550 | We could probably, in principle, infer minds from brains, and brains from minds [Russell] |
| 3631 | A blind man may still contain the idea of colour [Descartes] |
| 7551 | Matter is a logical construction [Russell] |
| 7547 | Matter requires a division into time-corpuscles as well as space-corpuscles [Russell] |
| 7552 | Six dimensions are needed for a particular, three within its own space, and three to locate that space [Russell] |
| 3640 | Possible existence is a perfection in the idea of a triangle [Descartes] |
| 3639 | Necessary existence is a property which is uniquely part of God's essence [Descartes] |