Combining Texts

All the ideas for 'fragments/reports', 'Emile: treatise on education' and 'Paradoxes of the Infinite'

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6 ideas

4. Formal Logic / F. Set Theory ST / 1. Set Theory
An aggregate in which order does not matter I call a 'set' [Bolzano]
     Full Idea: An aggregate whose basic conception renders the arrangement of its members a matter of indifference, and whose permutation therefore produces no essential difference, I call a 'set'.
     From: Bernard Bolzano (Paradoxes of the Infinite [1846], §4), quoted by William W. Tait - Frege versus Cantor and Dedekind IX
     A reaction: The idea of 'sets' was emerging before Cantor formalised it, and clarified it by thinking about infinite sets. Nowadays we also have 'ordered' sets, which rather contradicts Bolzano, and we also expect the cardinality to be determinate.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
A truly infinite quantity does not need to be a variable [Bolzano]
     Full Idea: A truly infinite quantity (for example, the length of a straight line, unbounded in either direction) does not by any means need to be a variable.
     From: Bernard Bolzano (Paradoxes of the Infinite [1846]), quoted by Brian Clegg - Infinity: Quest to Think the Unthinkable §10
     A reaction: This is an important idea, followed up by Cantor, which relegated to the sidelines the view of infinity as simply something that could increase without limit. Personally I like the old view, but there is something mathematically stable about infinity.
23. Ethics / F. Existentialism / 6. Authentic Self
Feelings are prior to intelligence; we should be content to live with our simplest feelings [Rousseau]
     Full Idea: To exist is to feel, our feeling is undoubtedly earlier than our intelligence, and we had feelings before we had ideas. …Let us be simpler and less pretentious; let us be content with the first feelings we experience in ourselves.
     From: Jean-Jacques Rousseau (Emile: treatise on education [1762], p.210), quoted by Kevin Aho - Existentialism: an introduction 6 'Moods'
     A reaction: Beginning of the sentimental movement, and precursor to romanticism, but here seen as the basis for the existentialist concept of authenticity. Wallowing in emotions doesn't appeal to me, but you have to make space for them. Rousseau loved walking.
24. Political Theory / B. Nature of a State / 4. Citizenship
We all owe labour in return for our keep, and every idle citizen is a thief [Rousseau]
     Full Idea: In a society where a man has to live at others' expense, he owes in labour the price of his keep; and that is without exception. Work, then, is an indispensable social obligation. Rich or poor, powerful or weak, every idle citizen is a thief.
     From: Jean-Jacques Rousseau (Emile: treatise on education [1762], Bk III)
     A reaction: Presumably rich landowners who live on rents can justify their position by good husbandry, at a higher level than tilling the soil. But Bertie Wooster won't last long in Rousseau's new world. This is a big challenge to the welfare state.
26. Natural Theory / A. Speculations on Nature / 5. Infinite in Nature
Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius]
     Full Idea: Archelaus was the first person to say that the universe is boundless.
     From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3
27. Natural Reality / G. Biology / 3. Evolution
Archelaus said life began in a primeval slime [Archelaus, by Schofield]
     Full Idea: Archelaus wrote that life on Earth began in a primeval slime.
     From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus
     A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea.