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### Ideas of Shaughan Lavine, by Text

#### [American, fl. 2006, Professor at the University of Arizona.]

 1994 Understanding the Infinite
 2.5 p.33 18250 Cauchy gave a necessary condition for the convergence of a sequence
 I p.4 15898 The controversy was not about the Axiom of Choice, but about functions as arbitrary, or given by rules
 I p.5 15899 Replacement was immediately accepted, despite having very few implications
 I p.5 15900 The iterative conception of set wasn't suggested until 1947
 II.6 p.38 15904 The two sides of the Cut are, roughly, the bounding commensurable ratios
 III.2 p.47 15907 Mathematics is nowadays (thanks to set theory) regarded as the study of structure, not of quantity
 III.3 p.50 15909 'Aleph-0' is cardinality of the naturals, 'aleph-1' the next cardinal, 'aleph-ω' the ω-th cardinal
 III.4 p.53 15912 Counting results in well-ordering, and well-ordering makes counting possible
 III.4 p.53 15913 A collection is 'well-ordered' if there is a least element, and all of its successors can be identified
 III.4 p.53 15914 An 'upper bound' is the greatest member of a subset; there may be several of these, so there is a 'least' one
 III.4 p.54 15915 Ordinals are basic to Cantor's transfinite, to count the sets
 III.5 p.61 15917 Paradox: the class of all ordinals is well-ordered, so must have an ordinal as type - giving a bigger ordinal
 III.5 p.62 15918 Paradox: there is no largest cardinal, but the class of everything seems to be the largest
 IV.1 p.63 15919 The 'logical' notion of class has some kind of definition or rule to characterise the class
 IV.2 p.78 15921 Collections of things can't be too big, but collections by a rule seem unlimited in size
 IV.2 p.78 15920 Pure collections of things obey Choice, but collections defined by a rule may not
 IV.2 p.92 15922 For the real numbers to form a set, we need the Continuum Hypothesis to be true
 V.3 p.123 15926 Second-order logic presupposes a set of relations already fixed by the first-order domain
 V.3 p.133 15929 Set theory will found all of mathematics - except for the notion of proof
 V.3 n33 p.132 15928 Intuitionism rejects set-theory to found mathematics
 V.4 p.135 15930 Foundation says descending chains are of finite length, blocking circularity, or ungrounded sets
 V.5 p.148 15931 The iterative conception needs the Axiom of Infinity, to show how far we can iterate
 V.5 p.149 15932 The iterative conception doesn't unify the axioms, and has had little impact on mathematical proofs
 V.5 p.150 15933 Limitation of Size: if it's the same size as a set, it's a set; it uses Replacement
 VI.1 p.155 15934 Mathematical proof by contradiction needs the law of excluded middle
 VI.1 p.157 15935 Modern mathematics works up to isomorphism, and doesn't care what things 'really are'
 VI.1 p.160 15936 The Power Set is just the collection of functions from one collection to another
 VI.2 p.164 15937 Those who reject infinite collections also want to reject the Axiom of Choice
 VI.2 p.176 15940 The intuitionist endorses only the potential infinite
 VI.3 p.198 15942 Every rational number, unlike every natural number, is divisible by some other number
 VII.4 p.226 15945 Second-order set theory just adds a version of Replacement that quantifies over functions
 VIII.2 p.248 15947 The infinite is extrapolation from the experience of indefinitely large size
 VIII.2 p.256 15949 The theory of infinity must rest on our inability to distinguish between very large sizes