Combining Texts

All the ideas for 'Set Theory and related topics (2nd ed)', 'On Motion' and 'The Idea of Equality'

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6 ideas

4. Formal Logic / F. Set Theory ST / 3. Types of Set / e. Equivalence classes
Equivalence relations are reflexive, symmetric and transitive, and classify similar objects [Lipschutz]
     Full Idea: A relation R on a non-empty set S is an equivalence relation if it is reflexive (for each member a, aRa), symmetric (if aRb, then bRa), and transitive (aRb and bRc, so aRc). It tries to classify objects that are in some way 'alike'.
     From: Seymour Lipschutz (Set Theory and related topics (2nd ed) [1998], 3.9)
     A reaction: So this is an attempt to formalise the common sense notion of seeing that two things have something in common. Presumably a 'way' of being alike is going to be a property or a part
23. Ethics / C. Virtue Theory / 3. Virtues / h. Respect
Equality of opportunity without equality of respect would create a very inhuman society [Williams,B]
     Full Idea: A highly rational, efficient and unmitigated application of the idea of equality of opportunity, while abandoning the idea of equality of respect as vague and nostalgic, would lead to a quite inhuman society.
     From: Bernard Williams (The Idea of Equality [1962], §3)
25. Social Practice / B. Equalities / 1. Grounds of equality
Equality seems to require that each person be acknowledged as having a significant point of view [Williams,B]
     Full Idea: Equality seems to require that each person is owed an effort at identification; they should not be seen as a surface to which a label can be applied, but one should try to see the world (including the label) from their point of view.
     From: Bernard Williams (The Idea of Equality [1962], §2)
Equality implies that people are alike in potential as well as in needs [Williams,B]
     Full Idea: Supporters of equality have asserted that people are alike in certain things they could do or achieve, as well as in the things that they need and could suffer.
     From: Bernard Williams (The Idea of Equality [1962], §2)
25. Social Practice / B. Equalities / 4. Economic equality
It is a mark of extreme exploitation that the sufferers do not realise their plight [Williams,B]
     Full Idea: It is a mark of extreme exploitation or degradation that those who suffer it do NOT see themselves differently from the way they are seen by the exploiters.
     From: Bernard Williams (The Idea of Equality [1962], §2)
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.