7 ideas
| 17744 | De Morgan started the study of relations and their properties [De Morgan, by Walicki] |
| Full Idea: De Morgan started the sustained interest in the study of relations and their properties. | |
| From: report of Augustus De Morgan (On the Syllogism IV [1859]) by Michal Walicki - Introduction to Mathematical Logic History D.1.1 |
| 13501 | De Morgan found inferences involving relations, which eluded Aristotle's syllogistic [De Morgan, by Hart,WD] |
| Full Idea: There was a prejudice against relations (in favour of properties) but De Morgan and others that impeccable inferences turn on relations and elude Aristotle's syllogistic. Thus: All horses are animals. Hence, all heads of horses are heads of animals. | |
| From: report of Augustus De Morgan (On the Syllogism IV [1859]) by William D. Hart - The Evolution of Logic 4 | |
| A reaction: This is actually an early example of modern analytic philosophy in action. You start with the inferences, and then work back to the ontology and the definition of concepts. But in pinning down such concepts, do we miss their full meaning? |
| 19216 | Propositions (such as 'that dog is barking') only exist if their items exist [Williamson] |
| Full Idea: A proposition about an item exists only if that item exists... how could something be the proposition that that dog is barking in circumstances in which that dog does not exist? | |
| From: Timothy Williamson (Necessary Existents [2002], p.240), quoted by Trenton Merricks - Propositions | |
| A reaction: This is a view of propositions I can't make sense of. If I'm under an illusion that there is a dog barking nearby, when there isn't one, can I not say 'that dog is barking'? If I haven't expressed a proposition, what have I done? |
| 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) |
| 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. |
| 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. |