59 ideas
9641 | Definitions should be replaceable by primitives, and should not be creative [Brown,JR] |
9634 | Set theory says that natural numbers are an actual infinity (to accommodate their powerset) [Brown,JR] |
9615 | Nowadays conditions are only defined on existing sets [Brown,JR] |
9613 | Naïve set theory assumed that there is a set for every condition [Brown,JR] |
9617 | The 'iterative' view says sets start with the empty set and build up [Brown,JR] |
9642 | A flock of birds is not a set, because a set cannot go anywhere [Brown,JR] |
9605 | If a proposition is false, then its negation is true [Brown,JR] |
9649 | Axioms are either self-evident, or stipulations, or fallible attempts [Brown,JR] |
9638 | Berry's Paradox finds a contradiction in the naming of huge numbers [Brown,JR] |
9604 | Mathematics is the only place where we are sure we are right [Brown,JR] |
9622 | 'There are two apples' can be expressed logically, with no mention of numbers [Brown,JR] |
9648 | π is a 'transcendental' number, because it is not the solution of an equation [Brown,JR] |
9621 | Mathematics represents the world through structurally similar models. [Brown,JR] |
9646 | There is no limit to how many ways something can be proved in mathematics [Brown,JR] |
9647 | Computers played an essential role in proving the four-colour theorem of maps [Brown,JR] |
9643 | Set theory may represent all of mathematics, without actually being mathematics [Brown,JR] |
9644 | When graphs are defined set-theoretically, that won't cover unlabelled graphs [Brown,JR] |
9625 | To see a structure in something, we must already have the idea of the structure [Brown,JR] |
9628 | Sets seem basic to mathematics, but they don't suit structuralism [Brown,JR] |
9606 | The irrationality of root-2 was achieved by intellect, not experience [Brown,JR] |
9610 | Numbers are not abstracted from particulars, because each number is a particular [Brown,JR] |
9612 | There is an infinity of mathematical objects, so they can't be physical [Brown,JR] |
9620 | Empiricists base numbers on objects, Platonists base them on properties [Brown,JR] |
9630 | The most brilliant formalist was Hilbert [Brown,JR] |
9629 | For nomalists there are no numbers, only numerals [Brown,JR] |
9639 | Does some mathematics depend entirely on notation? [Brown,JR] |
9608 | There are no constructions for many highly desirable results in mathematics [Brown,JR] |
9645 | Constructivists say p has no value, if the value depends on Goldbach's Conjecture [Brown,JR] |
9619 | David's 'Napoleon' is about something concrete and something abstract [Brown,JR] |
9611 | 'Abstract' nowadays means outside space and time, not concrete, not physical [Brown,JR] |
9609 | The older sense of 'abstract' is where 'redness' or 'group' is abstracted from particulars [Brown,JR] |
9640 | A term can have not only a sense and a reference, but also a 'computational role' [Brown,JR] |
23590 | Criminal responsibility can be fully assigned to each member of a group [Walzer] |
23578 | Double Effect needs a double intention - to achieve the good, and minimise the evil [Walzer] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
23564 | Deep ethical theory is very controversial, but we have to live with higher ethical practice [Walzer] |
23568 | If whole states possess rights, there can be social relations between states [Walzer] |
23581 | The aim of reprisals is to enforce the rules of war [Walzer] |
23567 | Even non-violent intrusive acts between states count as aggression, if they justify resistance [Walzer] |
23570 | The only good reason for fighting is in defence of rights [Walzer] |
23571 | States can rightly pre-empt real and serious threats [Walzer] |
23582 | Reprisal is defensible, as an alternative to war [Walzer] |
23580 | States need not endure attacks passively, and successful reprisals are legitimate [Walzer] |
23588 | With nuclear weapons we have a permanent supreme emergency (which is unstable) [Walzer] |
23572 | Just wars are self-defence, or a rightful intercession in another's troubles [Walzer] |
23587 | Nuclear bombs are not for normal war; they undermine the 'just war', with a new morality [Walzer] |
23577 | Napoleon said 'I don't care about the deaths of a million men' [Walzer] |
23593 | Jus ad bellum and Jus in bello are independent; unjust wars can be fought in a just way [Walzer] |
23573 | For moral reasons, a just war must be a limited war [Walzer] |
23589 | Kidnapped sailors and volunteers have different obligations to the passengers [Walzer] |
23614 | Even aggressor soldiers are not criminals, so they have equal rights with their opponents [Walzer] |
23574 | The duties and moral status of loyal and obedient soldiers is the same in defence and aggression [Walzer] |
23575 | We can't blame soldiers for anything they do which clearly promotes victory [Walzer] |
23584 | Rejecting Combatant Equality allows just soldiers to be harsher, even to the extreme [Walzer] |
23579 | Soldiers will only protect civilians if they feel safe from them [Walzer] |
23586 | What matters in war is unacceptable targets, not unacceptable weapons [Walzer] |
23591 | If the oppressor is cruel, nonviolence is either surrender, or a mere gesture [Walzer] |
23592 | We can only lead war towards peace if we firmly enforce the rules of war [Walzer] |
9635 | Given atomism at one end, and a finite universe at the other, there are no physical infinities [Brown,JR] |