Combining Texts

All the ideas for 'The Sign of Four', 'Sources of Knowledge of Mathematics' and 'On Motion'

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3 ideas

6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Late in life Frege abandoned logicism, and saw the source of arithmetic as geometrical [Frege, by Chihara]
     Full Idea: Near the end of his life, Frege completely abandoned his logicism, and came to the conclusion that the source of our arithmetical knowledge is what he called 'the Geometrical Source of Knowledge'.
     From: report of Gottlob Frege (Sources of Knowledge of Mathematics [1922]) by Charles Chihara - A Structural Account of Mathematics Intro n3
     A reaction: We have, rather crucially, lost touch with the geometrical origins of arithmetic (such as 'square' numbers), which is good news for the practice of mathematics, but probably a disaster for the philosophy of the subject.
14. Science / C. Induction / 1. Induction
If you eliminate the impossible, the truth will remain, even if it is weird [Conan Doyle]
     Full Idea: When you have eliminated the impossible, whatever remains, however improbable, must be the truth.
     From: Arthur Conan Doyle (The Sign of Four [1890], Ch. 6)
     A reaction: A beautiful statement, by Sherlock Holmes, of Eliminative Induction. It is obviously not true, of course. Many options may still face you after you have eliminated what is actually impossible.
27. Natural Reality / B. Modern Physics / 1. Relativity / a. Special relativity
Motion is not absolute, but consists in relation [Leibniz]
     Full Idea: In reality motion is not something absolute, but consists in relation.
     From: Gottfried Leibniz (On Motion [1677], A6.4.1968), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 3
     A reaction: It is often thought that motion being relative was invented by Einstein, but Leibniz wholeheartedly embraced 'Galilean relativity', and refused to even consider any absolute concept of motion. Acceleration is a bit trickier than velocity.