Combining Texts
Ideas for
'Thinking About Mathematics', 'Reply to First Objections' and 'Understanding the Infinite'
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29 ideas
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
15907
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Mathematics is nowadays (thanks to set theory) regarded as the study of structure, not of quantity [Lavine]
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6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
8763
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The number 3 is presumably identical as a natural, an integer, a rational, a real, and complex [Shapiro]
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15942
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Every rational number, unlike every natural number, is divisible by some other number [Lavine]
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6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
15922
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For the real numbers to form a set, we need the Continuum Hypothesis to be true [Lavine]
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6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / h. Reals from Cauchy
18249
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Cauchy gave a formal definition of a converging sequence. [Shapiro]
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18250
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Cauchy gave a necessary condition for the convergence of a sequence [Lavine]
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6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / i. Reals from cuts
15904
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The two sides of the Cut are, roughly, the bounding commensurable ratios [Lavine]
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6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
15912
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Counting results in well-ordering, and well-ordering makes counting possible [Lavine]
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6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
15949
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The theory of infinity must rest on our inability to distinguish between very large sizes [Lavine]
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15947
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The infinite is extrapolation from the experience of indefinitely large size [Lavine]
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6. Mathematics / A. Nature of Mathematics / 5. The Infinite / c. Potential infinite
15940
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The intuitionist endorses only the potential infinite [Lavine]
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6. Mathematics / A. Nature of Mathematics / 5. The Infinite / f. Uncountable infinities
15909
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'Aleph-0' is cardinality of the naturals, 'aleph-1' the next cardinal, 'aleph-ω' the ω-th cardinal [Lavine]
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6. Mathematics / A. Nature of Mathematics / 5. The Infinite / h. Ordinal infinity
15915
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Ordinals are basic to Cantor's transfinite, to count the sets [Lavine]
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15917
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Paradox: the class of all ordinals is well-ordered, so must have an ordinal as type - giving a bigger ordinal [Lavine]
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6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
15918
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Paradox: there is no largest cardinal, but the class of everything seems to be the largest [Lavine]
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6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
8764
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Categories are the best foundation for mathematics [Shapiro]
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6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / f. Zermelo numbers
8762
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Two definitions of 3 in terms of sets disagree over whether 1 is a member of 3 [Shapiro]
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6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
15929
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Set theory will found all of mathematics - except for the notion of proof [Lavine]
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6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
8760
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Numbers do not exist independently; the essence of a number is its relations to other numbers [Shapiro]
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8761
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A 'system' is related objects; a 'pattern' or 'structure' abstracts the pure relations from them [Shapiro]
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6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / b. Against mathematical platonism
15935
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Modern mathematics works up to isomorphism, and doesn't care what things 'really are' [Lavine]
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6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
8744
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Logicism seems to be a non-starter if (as is widely held) logic has no ontology of its own [Shapiro]
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6. Mathematics / C. Sources of Mathematics / 7. Formalism
8749
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Term Formalism says mathematics is just about symbols - but real numbers have no names [Shapiro]
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8750
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Game Formalism is just a matter of rules, like chess - but then why is it useful in science? [Shapiro]
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8752
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Deductivism says mathematics is logical consequences of uninterpreted axioms [Shapiro]
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6. Mathematics / C. Sources of Mathematics / 10. Constructivism / b. Intuitionism
8753
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Critics resent the way intuitionism cripples mathematics, but it allows new important distinctions [Shapiro]
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15928
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Intuitionism rejects set-theory to found mathematics [Lavine]
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6. Mathematics / C. Sources of Mathematics / 10. Constructivism / c. Conceptualism
8731
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Conceptualist are just realists or idealist or nominalists, depending on their view of concepts [Shapiro]
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6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
8730
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'Impredicative' definitions refer to the thing being described [Shapiro]
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