55 ideas
17774 | Definitions make our intuitions mathematically useful [Mayberry] |
17773 | Proof shows that it is true, but also why it must be true [Mayberry] |
17795 | Set theory can't be axiomatic, because it is needed to express the very notion of axiomatisation [Mayberry] |
17796 | There is a semi-categorical axiomatisation of set-theory [Mayberry] |
17800 | The misnamed Axiom of Infinity says the natural numbers are finite in size [Mayberry] |
17801 | The set hierarchy doesn't rely on the dubious notion of 'generating' them [Mayberry] |
17803 | Limitation of size is part of the very conception of a set [Mayberry] |
17786 | The mainstream of modern logic sees it as a branch of mathematics [Mayberry] |
17788 | First-order logic only has its main theorems because it is so weak [Mayberry] |
17791 | Only second-order logic can capture mathematical structure up to isomorphism [Mayberry] |
17787 | Big logic has one fixed domain, but standard logic has a domain for each interpretation [Mayberry] |
17790 | No Löwenheim-Skolem logic can axiomatise real analysis [Mayberry] |
17779 | 'Classificatory' axioms aim at revealing similarity in morphology of structures [Mayberry] |
17778 | Axiomatiation relies on isomorphic structures being essentially the same [Mayberry] |
17780 | 'Eliminatory' axioms get rid of traditional ideal and abstract objects [Mayberry] |
17789 | No logic which can axiomatise arithmetic can be compact or complete [Mayberry] |
17784 | Real numbers can be eliminated, by axiom systems for complete ordered fields [Mayberry] |
17782 | Greek quantities were concrete, and ratio and proportion were their science [Mayberry] |
17781 | Real numbers were invented, as objects, to simplify and generalise 'quantity' [Mayberry] |
17799 | Cantor's infinite is an absolute, of all the sets or all the ordinal numbers [Mayberry] |
17797 | Cantor extended the finite (rather than 'taming the infinite') [Mayberry] |
17775 | If proof and definition are central, then mathematics needs and possesses foundations [Mayberry] |
17776 | The ultimate principles and concepts of mathematics are presumed, or grasped directly [Mayberry] |
17777 | Foundations need concepts, definition rules, premises, and proof rules [Mayberry] |
17804 | Axiom theories can't give foundations for mathematics - that's using axioms to explain axioms [Mayberry] |
17792 | 1st-order PA is only interesting because of results which use 2nd-order PA [Mayberry] |
17793 | It is only 2nd-order isomorphism which suggested first-order PA completeness [Mayberry] |
17794 | Set theory is not just first-order ZF, because that is inadequate for mathematics [Mayberry] |
17802 | We don't translate mathematics into set theory, because it comes embodied in that way [Mayberry] |
17805 | Set theory is not just another axiomatised part of mathematics [Mayberry] |
17785 | Real numbers as abstracted objects are now treated as complete ordered fields [Mayberry] |
9240 | Love creates a necessity concerning what to care about [Frankfurt] |
9264 | Persons are distinguished by a capacity for second-order desires [Frankfurt] |
9266 | A person essentially has second-order volitions, and not just second-order desires [Frankfurt] |
9267 | Free will is the capacity to choose what sort of will you have [Frankfurt] |
9265 | The will is the effective desire which actually leads to an action [Frankfurt] |
20015 | Freedom of action needs the agent to identify with their reason for acting [Frankfurt, by Wilson/Schpall] |
9228 | Ranking order of desires reveals nothing, because none of them may be considered important [Frankfurt] |
9270 | A 'wanton' is not a person, because they lack second-order volitions [Frankfurt] |
9269 | A person may be morally responsible without free will [Frankfurt] |
9238 | Morality isn't based on reason; moral indignation is quite unlike disapproval of irrationality [Frankfurt] |
9232 | It is by caring about things that we infuse the world with importance [Frankfurt] |
9234 | If you don't care about at least one thing, you can't find reasons to care about anything [Frankfurt] |
9229 | What is worthwhile for its own sake alone may be worth very little [Frankfurt] |
9233 | Our criteria for evaluating how to live offer an answer to the problem [Frankfurt] |
9235 | Rather than loving things because we value them, I think we value things because we love them [Frankfurt] |
9236 | Love can be cool, and it may not involve liking its object [Frankfurt] |
9237 | The paradigm case of pure love is not romantic, but that between parents and infants [Frankfurt] |
9239 | I value my children for their sake, but I also value my love for them for its own sake [Frankfurt] |
9227 | We might not choose a very moral life, if the character or constitution was deficient [Frankfurt] |
9230 | People want to fulfill their desires, but also for their desires to be sustained [Frankfurt] |
9241 | Loving oneself is not a failing, but is essential to a successful life [Frankfurt] |
9300 | Boredom is serious, not just uncomfortable; it threatens our psychic survival [Frankfurt] |
9231 | Freedom needs autonomy (rather than causal independence) - embracing our own desires and choices [Frankfurt] |
1513 | The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus] |