4 ideas
| 17743 | De Morgan introduced a 'universe of discourse', to replace Boole's universe of 'all things' [De Morgan, by Walicki] |
| Full Idea: In 1846 De Morgan introduced the enormously influential notion of a possibly arbitrary and stipulated 'universe of discourse'. It replaced Boole's original - and metaphysically a bit suspect - universe of 'all things'. | |
| From: report of Augustus De Morgan (works [1846]) by Michal Walicki - Introduction to Mathematical Logic History D.1.1 | |
| A reaction: This not only brings formal logic under control, but also reflects normal talk, because there is always an explicit or implicit domain of discourse when we talk. Of virtually any conversation, you can say what it is 'about'. |
| 6409 | The 'simple theory of types' distinguishes levels among properties [Ramsey, by Grayling] |
| Full Idea: The idea that there should be something like a distinction of levels among properties is captured in Ramsey's 'simple theory of types'. | |
| From: report of Frank P. Ramsey (works [1928]) by A.C. Grayling - Russell | |
| A reaction: I merely report this, though it is not immediately obvious how anyone would decide which 'level' a type belonged on. |
| 3212 | Beliefs are maps by which we steer [Ramsey] |
| Full Idea: Beliefs are maps by which we steer. | |
| From: Frank P. Ramsey (works [1928]), quoted by Georges Rey - Contemporary Philosophy of Mind p.259 n5 |
| 20919 | How can things without weight compose weight? [Alexander] |
| Full Idea: How could weight come about out of things composed of what is without weight? | |
| From: Alexander (On Aristotle's Metaphysics Book 2 [c.200], p.36.21-27) | |
| A reaction: This is obviously why Epicurus added weight to the features of atoms. Alexander seems unaware of this move. |