3 ideas
7726 | Aristotelian logic dealt with inferences about concepts, and there were also proposition inferences [Weiner] |
Full Idea: Till the nineteenth century, it was a common view that Aristotelian logic could evaluate inferences whose validity was based on relations between concepts, while propositional logic could evaluate inferences based on relations between propositions. | |
From: Joan Weiner (Frege [1999], Ch.3) | |
A reaction: Venn diagrams relate closely to Aristotelian syllogisms, as each concept is represented by a circle, and shows relations between sets. Arrows seem needed to represent how to go from one proposition to another. Is one static, the other dynamic? |
3061 | Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius] |
Full Idea: Anaxarchus said that he was not even sure that he knew nothing. | |
From: report of Anaxarchus (fragments/reports [c.340 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.10.1 |
15640 | Courage is not a virtue, but the form of every virtue at its testing point [Lewis,CS] |
Full Idea: Courage is not simply one of the virtues, but the form of every virtue at the testing point. | |
From: C.S. Lewis (works [1950]) | |
A reaction: This appeared on Twitter, without mention of its source. Adding it breaks my normal rules, but I hope you agree that it is too good to miss. Is not even resolutely facing up to suffering or death a case of genuine courage? Determination, prioritisation? |