Combining Texts

All the ideas for 'fragments/reports', 'works' and 'Paradoxes of the Infinite'

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7 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.
19. Language / A. Nature of Meaning / 6. Meaning as Use
Study the use of words, not their origins [Herder]
     Full Idea: Not how an expression can be etymologically derived and determined analytically, but how it is used is the question. Origin and use are often very different.
     From: Johann Gottfried Herder (works [1784], p.153), quoted by Andrew Bowie - Introduction to German Philosophy 2 'Herder'
     A reaction: This doesn't quite say that meaning is use, and is basically an attack on the Etymological Fallacy (that origin gives meaning), but it is a strikingly modern view of language.
22. Metaethics / B. Value / 1. Nature of Value / f. Ultimate value
We cannot attain all the ideals of every culture, so there cannot be a perfect life [Herder, by Berlin]
     Full Idea: For Herder, we cannot attain to the highest ideals of all the centuries and all the places at once, and since we cannot do that, the whole notion of the perfect life collapses.
     From: report of Johann Gottfried Herder (works [1784]) by Isaiah Berlin - The Roots of Romanticism Ch.3
     A reaction: Herder seems to be the father of modern cultural relativism. The idea is hard to challenge, but the ideals of some cultures should be ignored, if they diminish rather than enhance the good life for all.
24. Political Theory / D. Ideologies / 7. Communitarianism / a. Communitarianism
Herder invented the idea of being rooted in (or cut off from) a home or a group [Herder, by Berlin]
     Full Idea: The whole notion of being at home, or being cut off from one's natural roots, the whole idea of roots, the whole idea of belonging to a group, a sect, a movement, was largely invented by Herder.
     From: report of Johann Gottfried Herder (works [1784], Ch.3) by Isaiah Berlin - The Roots of Romanticism
     A reaction: Hm. Broad generalisations are an awful temptation in the history of ideas. As a corrective to this, trying reading the two Anglo-Saxon poems 'The Wanderer' and 'The Seafarer'. Very Germanic, I suppose. Interesting, though. Leads to Hegel's politics.
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.