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'. |
| 12712 | Substance is that which can act [Leibniz] |
| Full Idea: I define substance as that which can act. | |
| From: Gottfried Leibniz (Definitiones cogitationesque metaphysicae [1678], A6.4.1398), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 3 | |
| A reaction: This is in tune with the notion that to exist is to have causal powers. I find the view congenial, and the middle period of Leibniz's thought, before monads became too spiritual, chimes in with my view. |
| 12737 | Nature can be fully explained by final causes alone, or by efficient causes alone [Leibniz] |
| Full Idea: All the phenomena of nature can be explained solely by final causes, exactly as if there were no efficient causes; and all the phenomena of nature can be explained solely by efficient causes, as if there were no final causes. | |
| From: Gottfried Leibniz (Definitiones cogitationesque metaphysicae [1678], A6.4.1403), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 6 | |
| A reaction: Somewhat speculative (a virtue!), but it is interesting to see him suggesting that there might be two complete and satisfactory explanations, which never touched one another. I can't see Aristotle agreeing with that. |
| 22511 | Some reasonings are stronger than we are [Philolaus] |
| Full Idea: Some reasonings are stronger than we are. | |
| From: Philolaus (fragments/reports [c.425 BCE]), quoted by Aristotle - Eudemian Ethics 1225a33 | |
| A reaction: This endorses the Aristotle view of akrasia (as opposed to the Socratic view). This isolated remark seems to imply that we are more clearly embodiments of will than of reason. |