3 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'. |
| 19406 | I strongly believe in the actual infinite, which indicates the perfections of its author [Leibniz] |
| Full Idea: I am so much for the actual infinite that instead of admitting that nature abhors it, as is commonly said, I hold that it affects nature everywhere in order to indicate the perfections of its author. | |
| From: Gottfried Leibniz (Reply to Foucher [1693], p.99) | |
| A reaction: I would have thought that, for Leibniz, while infinities indicate the perfections of their author, that is not the reason why they exist. God wasn't, presumably, showing off. Leibniz does not think we can actually know these infinities. |
| 19458 | Egoism is the only evil, love the only good; genuine love produces all the other virtues [Feuerbach] |
| Full Idea: There is only one evil - egoism; there is only one good - love. ...Love, but truly! All other virtues will automatically come to you. | |
| From: Ludwig Feuerbach (Fragments on My Philosophical Development [1839], 1834-6) | |
| A reaction: This is a rather Christian idea of virtue, coming from the great atheist. Does tough love come from love? |