4 ideas
| 21554 | Sets always exceed terms, so all the sets must exceed all the sets [Lackey] |
| Full Idea: Cantor proved that the number of sets in a collection of terms is larger than the number of terms. Hence Cantor's Paradox says the number of sets in the collection of all sets must be larger than the number of sets in the collection of all sets. | |
| From: Douglas Lackey (Intros to Russell's 'Essays in Analysis' [1973], p.127) | |
| A reaction: The sets must count as terms in the next iteration, but that is a normal application of the Power Set axiom. |
| 21553 | It seems that the ordinal number of all the ordinals must be bigger than itself [Lackey] |
| Full Idea: The ordinal series is well-ordered and thus has an ordinal number, and a series of ordinals to a given ordinal exceeds that ordinal by 1. So the series of all ordinals has an ordinal number that exceeds its own ordinal number by 1. | |
| From: Douglas Lackey (Intros to Russell's 'Essays in Analysis' [1973], p.127) | |
| A reaction: Formulated by Burali-Forti in 1897. |
| 74 | Even God could not undo what has been done [Agathon] |
| Full Idea: One thing is denied even to God: to make what has been done undone again. | |
| From: Agathon (plays (frags) [c.410 BCE]), quoted by Aristotle - Nicomachean Ethics 1139b09 | |
| A reaction: a quotation - cf the Euthyphro Question |
| 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? |