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Ideas for 'fragments/reports', 'The Foundations of Empirical Knowledge' and 'On the Infinite'

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7 ideas

6. Mathematics / A. Nature of Mathematics / 1. Mathematics
We believe all mathematical problems are solvable [Hilbert]
     Full Idea: The thesis that every mathematical problem is solvable - we are all convinced that it really is so.
     From: David Hilbert (On the Infinite [1925], p.200)
     A reaction: This will include, for example, Goldbach's Conjecture (every even is the sum of two primes), which is utterly simple but with no proof anywhere in sight.
I aim to establish certainty for mathematical methods [Hilbert]
     Full Idea: The goal of my theory is to establish once and for all the certitude of mathematical methods.
     From: David Hilbert (On the Infinite [1925], p.184)
     A reaction: This is the clearest statement of the famous Hilbert Programme, which is said to have been brought to an abrupt end by Gödel's Incompleteness Theorems.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
No one shall drive us out of the paradise the Cantor has created for us [Hilbert]
     Full Idea: No one shall drive us out of the paradise the Cantor has created for us.
     From: David Hilbert (On the Infinite [1925], p.191), quoted by James Robert Brown - Philosophy of Mathematics
     A reaction: This is Hilbert's famous refusal to accept any account of mathematics, such as Kant's, which excludes actual infinities. Cantor had laid out a whole glorious hierarchy of different infinities.
We extend finite statements with ideal ones, in order to preserve our logic [Hilbert]
     Full Idea: To preserve the simple formal rules of ordinary Aristotelian logic, we must supplement the finitary statements with ideal statements.
     From: David Hilbert (On the Infinite [1925], p.195)
     A reaction: I find very appealing the picture of mathematics as rooted in the physical world, and then gradually extended by a series of 'idealisations', which should perhaps be thought of as fictions.
Only the finite can bring certainty to the infinite [Hilbert]
     Full Idea: Operating with the infinite can be made certain only by the finitary.
     From: David Hilbert (On the Infinite [1925], p.201)
     A reaction: See 'Compactness' for one aspect of this claim. I think Hilbert was fighting a rearguard action, and his idea now has few followers.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite
The idea of an infinite totality is an illusion [Hilbert]
     Full Idea: Just as in the limit processes of the infinitesimal calculus, the infinitely large and small proved to be a mere figure of speech, so too we must realise that the infinite in the sense of an infinite totality, used in deductive methods, is an illusion.
     From: David Hilbert (On the Infinite [1925], p.184)
     A reaction: This is a very authoritative rearguard action. I no longer think the dispute matters much, it being just a dispute over a proposed new meaning for the word 'number'.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / j. Infinite divisibility
There is no continuum in reality to realise the infinitely small [Hilbert]
     Full Idea: A homogeneous continuum which admits of the sort of divisibility needed to realise the infinitely small is nowhere to be found in reality.
     From: David Hilbert (On the Infinite [1925], p.186)
     A reaction: He makes this remark as a response to Planck's new quantum theory (the year before the big works of Heisenberg and Schrödinger). Personally I don't see why infinities should depend on the physical world, since they are imaginary.