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'. |
| 4871 | A thing is free if it acts only by the necessity of its own nature [Spinoza] |
| Full Idea: I say that a thing is free, which exists and acts solely by the necessity of its own nature. | |
| From: Baruch de Spinoza (Letter to G.H. Schaller [1674], 1674.10) | |
| A reaction: Of course, this isn't 'freedom' at all, but it seems to exactly right as an account of so-called freedom. In the case of a human being the 'necessity of our own nature' is character, and virtue and vice are the expressions of the necessities of character. |
| 7350 | The Torah just says: do not do to your neighbour what is hateful to you [Hillel the Elder] |
| Full Idea: What is hateful to you, do not unto your neighbour: this is the entire Torah. All the rest is commentary - go and study it. | |
| From: Hillel the Elder (reports [c.10]), quoted by Paul Johnson - The History of the Jews Pt II | |
| A reaction: Johnson suggests that this idea, of stripping everything from the Torah except its basic morality, was passed on to Jesus by Hillel. Suppose you hate Arsenal, but your neighbour supports them, and they just won the European Cup? What should you do? |