3 ideas
18189 | ZFC could contain a contradiction, and it can never prove its own consistency [MacLane] |
Full Idea: We have at hand no proof that the axioms of ZFC for set theory will never yield a contradiction, while Gödel's second theorem tells us that such a consistency proof cannot be conducted within ZFC. | |
From: Saunders MacLane (Mathematics: Form and Function [1986], p.406), quoted by Penelope Maddy - Naturalism in Mathematics | |
A reaction: Maddy quotes this, while defending set theory as the foundation of mathematics, but it clearly isn't the most secure foundation that could be devised. She says the benefits of set theory do not need guaranteed consistency (p.30). |
3016 | Even the gods cannot strive against necessity [Pittacus, by Diog. Laertius] |
Full Idea: Even the gods cannot strive against necessity. | |
From: report of Pittacus (reports [c.610 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 01.5.4 |
16714 | The state should kill blasphemous heretics [Erasmus] |
Full Idea: It is necessary for the preservation of the state to kill heretics that are blasphemous and seditious. | |
From: Desiderius Erasmus (works [1506]), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 20.2 | |
A reaction: He was much more tolerant of heretics who kept quiet. |