59 ideas
125 | Is a gifted philosopher unmanly if he avoids the strife of the communal world? [Plato] |
1654 | In "Gorgias" Socrates is confident that his 'elenchus' will decide moral truth [Vlastos on Plato] |
4321 | We should test one another, by asking and answering questions [Plato] |
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] |
579 | Cratylus said you couldn't even step into the same river once [Cratylus, by Aristotle] |
578 | Cratylus decided speech was hopeless, and his only expression was the movement of a finger [Cratylus, by Aristotle] |
114 | Rhetoric can produce conviction, but not educate people about right and wrong [Plato] |
116 | Rhetoric is irrational about its means and its ends [Plato] |
135 | All activity aims at the good [Plato] |
122 | Moral rules are made by the weak members of humanity [Plato] |
139 | A good person is bound to act well, and this brings happiness [Plato] |
128 | Is it natural to simply indulge our selfish desires? [Plato] |
4322 | In slaking our thirst the goodness of the action and the pleasure are clearly separate [Plato] |
136 | Good should be the aim of pleasant activity, not the other way round [Plato] |
134 | Good and bad people seem to experience equal amounts of pleasure and pain [Plato] |
132 | If happiness is the satisfaction of desires, then a life of scratching itches should be happiness [Plato] |
4319 | In a fool's mind desire is like a leaky jar, insatiable in its desires, and order and contentment are better [Plato] |
130 | Is the happiest state one of sensual, self-indulgent freedom? [Plato] |
120 | Should we avoid evil because it will bring us bad consequences? [Plato] |
118 | I would rather be a victim of crime than a criminal [Plato] |
140 | Self-indulgent desire makes friendship impossible, because it makes a person incapable of co-operation [Plato] |
131 | If absence of desire is happiness, then nothing is happier than a stone or a corpse [Plato] |
119 | A criminal is worse off if he avoids punishment [Plato] |
129 | Do most people praise self-discipline and justice because they are too timid to gain their own pleasure? [Plato] |
4320 | The popular view is that health is first, good looks second, and honest wealth third [Plato] |
137 | As with other things, a good state is organised and orderly [Plato] |
141 | A good citizen won't be passive, but will redirect the needs of the state [Plato] |
123 | Do most people like equality because they are second-rate? [Plato] |
124 | Does nature imply that it is right for better people to have greater benefits? [Plato] |