Combining Texts

All the ideas for 'Science and Method', 'The Individual, the State, and the Common Good' and 'Cours d'Analyse'

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4 ideas

6. Mathematics / A. Nature of Mathematics / 2. Geometry
One geometry cannot be more true than another [Poincaré]
     Full Idea: One geometry cannot be more true than another; it can only be more convenient.
     From: Henri Poincaré (Science and Method [1908], p.65), quoted by Stewart Shapiro - Philosophy of Mathematics
     A reaction: This is the culminating view after new geometries were developed by tinkering with Euclid's parallels postulate.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / k. Infinitesimals
Values that approach zero, becoming less than any quantity, are 'infinitesimals' [Cauchy]
     Full Idea: When the successive absolute values of a variable decrease indefinitely in such a way as to become less than any given quantity, that variable becomes what is called an 'infinitesimal'. Such a variable has zero as its limit.
     From: Augustin-Louis Cauchy (Cours d'Analyse [1821], p.19), quoted by Philip Kitcher - The Nature of Mathematical Knowledge 10.4
     A reaction: The creator of the important idea of the limit still talked in terms of infinitesimals. In the next generation the limit took over completely.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / l. Limits
When successive variable values approach a fixed value, that is its 'limit' [Cauchy]
     Full Idea: When the values successively attributed to the same variable approach indefinitely a fixed value, eventually differing from it by as little as one could wish, that fixed value is called the 'limit' of all the others.
     From: Augustin-Louis Cauchy (Cours d'Analyse [1821], p.19), quoted by Philip Kitcher - The Nature of Mathematical Knowledge 10.4
     A reaction: This seems to be a highly significan proposal, because you can now treat that limit as a number, and adds things to it. It opens the door to Cantor's infinities. Is the 'limit' just a fiction?
24. Political Theory / D. Ideologies / 6. Liberalism / g. Liberalism critique
Liberalism may fail because it neglects the shared nature of what we pursue and protect [Haldane]
     Full Idea: I am interested in the claim that liberalism fails inasmuch as it neglects, and cannot accommodate, the fact that some or all of the goods we pursue, and which a system of rights is concerned to protect, are goods possessed in common.
     From: John Haldane (The Individual, the State, and the Common Good [1996], III)
     A reaction: It depends how individualistic we take liberalism to be. Extreme individualism (Nozick) strikes me as crazy. If 'we' erect a statue to some dubious politicians, it might be presented as a common good, but actually be despised by many.