display all the ideas for this combination of texts
3 ideas
| 22609 | Philosophers accepted first-order logic, because they took science to be descriptive, not explanatory [Ingthorsson] |
| Full Idea: First-order predicate logic was accepted so easily by the philosophical community …because philosophy was already geared toward a neo-Humean view of both science and philosophy as primarily descriptive rather than explanatory. | |
| From: R.D. Ingthorsson (A Powerful Particulars View of Causation [2021], 1.8) | |
| A reaction: The point, I think, is that explanatory thinking needs second-order logic, where the properties (or powers) are players in the game, and not just adjuncts of the catalogue of objects. I find this idea mind-expanding. (That's a good thing). |
| 8078 | Modus ponens is one of five inference rules identified by the Stoics [Chrysippus, by Devlin] |
| Full Idea: Modus ponens is just one of the five different inference rules identified by the Stoics. | |
| From: report of Chrysippus (fragments/reports [c.240 BCE]) by Keith Devlin - Goodbye Descartes Ch.2 | |
| A reaction: Modus ponens strikes me as being more like a definition of implication than a 'rule'. Implication is what gets you from one truth to another. All the implications of a truth must also be true. |
| 6023 | Every proposition is either true or false [Chrysippus, by Cicero] |
| Full Idea: We hold fast to the position, defended by Chrysippus, that every proposition is either true or false. | |
| From: report of Chrysippus (fragments/reports [c.240 BCE]) by M. Tullius Cicero - On Fate ('De fato') 38 | |
| A reaction: I am intrigued to know exactly how you defend this claim. It may depend what you mean by a proposition. A badly expressed proposition may have indeterminate truth, quite apart from the vague, the undecidable etc. |