6 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? |
| 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'. |
| 19000 | Read 'all ravens are black' as about ravens, not as about an implication [Belnap] |
| Full Idea: 'All ravens are black' might profitably be read as saying not that being a raven 'implies' being black, but rather something more like 'Consider the ravens: each one is black'. | |
| From: Nuel D. Belnap (Conditional Assertion and Restricted Quantification [1970], p.7), quoted by Stephen Yablo - Aboutness 04.5 | |
| A reaction: Belnap is more interested in the logic than in the paradox of confirmation, since he evidently thinks that universal generalisations should not be read as implications. I like Belnap's suggestion. |
| 17897 | Analytic explanation is wholes in terms of parts; synthetic is parts in terms of wholes or contexts [Belnap] |
| Full Idea: Throughout the whole texture of philosophy we distinguish two modes of explanation: the analytic mode, which tends to explain wholes in terms of parts, and the synthetic mode, which explains parts in terms of the wholes or contexts in which they occur. | |
| From: Nuel D. Belnap (Tonk, Plonk and Plink [1962], p.132) | |
| A reaction: The analytic would be bottom-up, and the synthetic would be top-down. I'm inclined to combine them, and say explanation begins with a model, which can then be sliced in either direction, though the bottom looks more interesting. |
| 7810 | The 'Eumenides' of Aeschylus shows blood feuds replaced by law [Aeschylus, by Grayling] |
| Full Idea: The 'Eumenides' of Aeschylus tells how the old rule of revenge and blood feud was replaced by a due process of law before a civil jury. | |
| From: report of Aeschylus (The Eumenides [c.458 BCE]) by A.C. Grayling - What is Good? Ch.2 | |
| A reaction: Compare Idea 1659, where this revolution is attributed to Protagoras (a little later than Aeschylus). I take the rule of law and of society to be above all the rule of reason, because the aim is calm objectivity instead of emotion. |