9 ideas
13472 | Hilbert aimed to eliminate number from geometry [Hilbert, by Hart,WD] |
Full Idea: One of Hilbert's aims in 'The Foundations of Geometry' was to eliminate number [as measure of lengths and angles] from geometry. | |
From: report of David Hilbert (Foundations of Geometry [1899]) by William D. Hart - The Evolution of Logic 2 | |
A reaction: Presumably this would particularly have to include the elimination of ratios (rather than actual specific lengths). |
9546 | Euclid axioms concerns possibilities of construction, but Hilbert's assert the existence of objects [Hilbert, by Chihara] |
Full Idea: Hilbert's geometrical axioms were existential in character, asserting the existence of certain geometrical objects (points and lines). Euclid's postulates do not assert the existence of anything; they assert the possibility of certain constructions. | |
From: report of David Hilbert (Foundations of Geometry [1899]) by Charles Chihara - A Structural Account of Mathematics 01.1 | |
A reaction: Chihara says geometry was originally understood modally, but came to be understood existentially. It seems extraordinary to me that philosophers of mathematics can have become more platonist over the centuries. |
18742 | Hilbert's formalisation revealed implicit congruence axioms in Euclid [Hilbert, by Horsten/Pettigrew] |
Full Idea: In his formal investigation of Euclidean geometry, Hilbert uncovered congruence axioms that implicitly played a role in Euclid's proofs but were not explicitly recognised. | |
From: report of David Hilbert (Foundations of Geometry [1899]) by Horsten,L/Pettigrew,R - Mathematical Methods in Philosophy 2 | |
A reaction: The writers are offering this as a good example of the benefits of a precise and formal approach to foundational questions. It's hard to disagree, but dispiriting if you need a PhD in maths before you can start doing philosophy. |
18217 | Hilbert's geometry is interesting because it captures Euclid without using real numbers [Hilbert, by Field,H] |
Full Idea: Hilbert's formulation of the Euclidean theory is of special interest because (besides being rigorously axiomatised) it does not employ the real numbers in the axioms. | |
From: report of David Hilbert (Foundations of Geometry [1899]) by Hartry Field - Science without Numbers 3 | |
A reaction: Notice that this job was done by Hilbert, and not by the fictionalist Hartry Field. |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |
20482 | Virtue inspires Stoics, but I want a good temperament [Montaigne] |
Full Idea: What Stoics did from virtue I teach myself to do from temperament. | |
From: Michel de Montaigne (III.10 On Restraining your Will [1580], p.1153) | |
A reaction: I take this to be an Aristotelian criticism of Stoicism. They venerate virtue above everything, but Aristotle says you must integrate virtue into your very being, so that right actions flow from you, with very little need for premeditation. |
20480 | There is not much point in only becoming good near the end of your life [Montaigne] |
Full Idea: It is almost better never to become a good man at all than to do so tardily, understanding how to live when you have no life left. | |
From: Michel de Montaigne (III.10 On Restraining your Will [1580], p.1142) | |
A reaction: A very nice perspective, which I don't recall Aristotle mentioning. It does, though, reinforce Aristotle's belief that early training is essential. |
20481 | Nothing we say can be worse than unsaying it in the face of authority [Montaigne] |
Full Idea: Nothing which a gentleman says can seem worse than the shame of his unsaying it under duress from authority. | |
From: Michel de Montaigne (III.10 On Restraining your Will [1580], p.1153) | |
A reaction: The point is that you have to fight every day for free speech, because no matter what the law says, there are always people in power who want to shut you up. |
20479 | People at home care far more than soldiers risking death about the outcome of wars [Montaigne] |
Full Idea: How many soldiers put themselves at risk every day in wars which they care little about, rushing into danger in battles the loss of which will not make them lose a night's sleep. Meanwhile a man at home is more passionate about the war than the soldier. | |
From: Michel de Montaigne (III.10 On Restraining your Will [1580], p.1139) | |
A reaction: It depends whether you are a mercenary (which the majority probably were in 1680), and what are the implications of defeat. |