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All the ideas for '', 'Gdel's Proof' and 'talk'

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6 ideas

1. Philosophy / A. Wisdom / 2. Wise People
If you hope to improve the world, all you can do is improve yourself [Wittgenstein]
     Full Idea: When Wittgenstein was once asked what one can do to improve the world, he replied: 'Improve yourself; that is the only thing you can do to improve the world'.
     From: Ludwig Wittgenstein (talk [1935]), quoted by Ray Monk - Bertrand Russell: Ghost of Madness Ch.1
     A reaction: This is rather startlingly pessimistic about politics, and I don't really believe it. If anything has ever improved me, it has usually come from the world, and been created by other people.
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt]
     Full Idea: If a designated conclusion follows from the premisses, but the argument involves two howlers which cancel each other out, then the moral is that the path an argument takes from premisses to conclusion does matter to its logical evaluation.
     From: Ian Rumfitt ("Yes" and "No" [2000], II)
     A reaction: The drift of this is that our view of logic should be a little closer to the reasoning of ordinary language, and we should rely a little less on purely formal accounts.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt]
     Full Idea: If 'and' and 'but' really are alike in sense, in what might that likeness consist? Some philosophers of classical logic will reply that they share a sense by virtue of sharing a truth table.
     From: Ian Rumfitt ("Yes" and "No" [2000])
     A reaction: This is the standard view which Rumfitt sets out to challenge.
The sense of a connective comes from primitively obvious rules of inference [Rumfitt]
     Full Idea: A connective will possess the sense that it has by virtue of its competent users' finding certain rules of inference involving it to be primitively obvious.
     From: Ian Rumfitt ("Yes" and "No" [2000], III)
     A reaction: Rumfitt cites Peacocke as endorsing this view, which characterises the logical connectives by their rules of usage rather than by their pure semantic value.
18. Thought / A. Modes of Thought / 5. Rationality / b. Human rationality
The human intellect has not been, and cannot be, fully formalized [Nagel/Newman]
     Full Idea: The resources of the human intellect have not been, and cannot be, fully formalized.
     From: E Nagel / JR Newman (Gödel's Proof [1958], VIII)
     A reaction: This conclusion derives from Gödel's Theorem. Some people (e.g. Penrose) get over-excited by this discovery, and conclude that the human mind is supernatural. Imagination is the key - it is a feature of rationality that escapes mechanization.
19. Language / F. Communication / 3. Denial
We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt]
     Full Idea: The standard view is that affirming not-A is more complex than affirming the atomic sentence A itself, with the latter determining its sense. But we could learn 'not' directly, by learning at once how to either affirm A or reject A.
     From: Ian Rumfitt ("Yes" and "No" [2000], IV)
     A reaction: [compressed] This seems fairly anti-Fregean in spirit, because it looks at the psychology of how we learn 'not' as a way of clarifying what we mean by it, rather than just looking at its logical behaviour (and thus giving it a secondary role).