6 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'. |
| 19284 | Asserting a necessity just expresses our inability to imagine it is false [Blackburn] |
| Full Idea: To say that we dignify a truth as necessary we are expressing our own mental attitudes - our own inability to make anything of a possible way of thinking which denies it. It is this blank unimaginability which we voice when we use the modal vocabulary. | |
| From: Simon Blackburn (Spreading the Word [1984], 6.5) | |
| A reaction: Yes, but why are we unable to imagine it? I accept that the truth or falsity of Goldbach's Conjecture may well be necessary, but I have no imagination one way or the other about it. Philosophers like Blackburn are very alien to me! |
| 13554 | True greatness is never allowing events to disturb you [Seneca] |
| Full Idea: There is no more reliable proof of greatness than to be in a state where nothing can happen to make you disturbed. | |
| From: Seneca the Younger (On Anger (Book 3) [c.60], §06) | |
| A reaction: He specifically opposes Aristotle's view that there are times when anger is appropriate, and failure to be very angry indeed is a failure of character. |
| 13556 | Every night I critically review how I have behaved during the day [Seneca] |
| Full Idea: When the lamp has been removed from my sight, and my wife, no stranger now to my habit, has fallen silent, I examine the whole of my day and retrace my actions and words; I hide nothing from myself. | |
| From: Seneca the Younger (On Anger (Book 3) [c.60], §36) |
| 13552 | Anger is an extreme vice, threatening sanity, and gripping whole states [Seneca] |
| Full Idea: Other vices drive the mind on, anger hurls it headlong; ..other vices revolt from good sense, this one from sanity; ...other vices seize individuals, this is the one passion that sometimes takes hold of an entire state. | |
| From: Seneca the Younger (On Anger (Book 3) [c.60], §01) | |
| A reaction: He particularly dislikes anger because it is the vice that leads to violence. |
| 13553 | Anger is a vice which afflicts good men as well as bad [Seneca] |
| Full Idea: Other vile passions affect only the worst sort of men, but anger creeps up even on enlightened me who are otherwise sane. | |
| From: Seneca the Younger (On Anger (Book 3) [c.60], §04) | |
| A reaction: A very interesting observation for anyone who is trying to analyse the key issues in virtue theory. |