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9390
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Logic guides thinking, but it isn't a substitute for it [Rumfitt]
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Full Idea:
Logic is part of a normative theory of thinking, not a substitute for thinking.
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From:
Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.13)
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A reaction:
There is some sort of logicians' dream, going back to Leibniz, of a reasoning engine, which accepts propositions and outputs inferences. I agree with this idea. People who excel at logic are often, it seems to me, modest at philosophy.
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14182
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If the logic of 'taller of' rests just on meaning, then logic may be the study of merely formal consequence [Read]
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Full Idea:
In 'A is taller than B, and B is taller than C, so A is taller than C' this can been seen as a matter of meaning - it is part of the meaning of 'taller' that it is transitive, but not of logic. Logic is now seen as the study of formal consequence.
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From:
Stephen Read (Formal and Material Consequence [1994], 'Reduct')
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A reaction:
I think I find this approach quite appealing. Obviously you can reason about taller-than relations, by putting the concepts together like jigsaw pieces, but I tend to think of logic as something which is necessarily implementable on a machine.
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14184
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In modus ponens the 'if-then' premise contributes nothing if the conclusion follows anyway [Read]
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Full Idea:
A puzzle about modus ponens is that the major premise is either false or unnecessary: A, If A then B / so B. If the major premise is true, then B follows from A, so the major premise is redundant. So it is false or not needed, and contributes nothing.
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From:
Stephen Read (Formal and Material Consequence [1994], 'Repres')
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A reaction:
Not sure which is the 'major premise' here, but it seems to be saying that the 'if A then B' is redundant. If I say 'it's raining so the grass is wet', it seems pointless to slip in the middle the remark that rain implies wet grass. Good point.
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14186
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Logical connectives contain no information, but just record combination relations between facts [Read]
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Full Idea:
The logical connectives are useful for bundling information, that B follows from A, or that one of A or B is true. ..They import no information of their own, but serve to record combinations of other facts.
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From:
Stephen Read (Formal and Material Consequence [1994], 'Repres')
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A reaction:
Anyone who suggests a link between logic and 'facts' gets my vote, so this sounds a promising idea. However, logical truths have a high degree of generality, which seems somehow above the 'facts'.
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9389
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Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt]
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Full Idea:
Vagueness in respect of membership is consistency with determinacy of the set's identity, so long as a set's identity is taken to consist, not in its having such-and-such members, but in its being the extension of a concept.
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From:
Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.5)
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A reaction:
I find this view of sets much more appealing than the one that identifies a set with its members. The empty set is less of a problem, as well as non-existents. Logicians prefer the extensional view because it is tidy.
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7590
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Consequentialism emphasises value rather than obligation in morality [Scruton]
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Full Idea:
According to consequentialism, the fundamental concept of morality is not obligation (deontological ethics) but value (axiological ethics).
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From:
Roger Scruton (A Dictionary of Political Thought [1982], 'consequentialism')
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A reaction:
These two views could come dramatically apart, in wartime, or in big ecological crises, or in a family breakup, or in religious disputes. Having identified the pair so clearly, why can we not aim for a civilised (virtuous) balance between the two?
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7589
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Altruism is either emotional (where your interests are mine) or moral (where they are reasons for me) [Scruton]
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Full Idea:
Two distinct motives go by the name of altruism: the emotions of liking, love and friendship, making another's interest automatically mine; and the moral motive of respect or considerateness, where another's interests become reasons for me, but not mine.
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From:
Roger Scruton (A Dictionary of Political Thought [1982], 'altruism')
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A reaction:
The second one has a strongly Kantian flavour, with its notion of impersonal duty. Virtue theorists will aspire to achieve the first state rather than the second, because good actions are then actively desired, and give pleasure to the doer.
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7593
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Liberals focus on universal human freedom, natural rights, and tolerance [Scruton, by PG]
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Full Idea:
Liberalism believes (roughly) in the supremacy of the individual, who has freedom and natural rights; it focuses on human, not divine affairs; it claims rights and duties are universal; and it advocates tolerance in religion and morality.
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From:
report of Roger Scruton (A Dictionary of Political Thought [1982], 'liberalism') by PG - Db (ideas)
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A reaction:
I find it hard to disagree with these principles, but the upshot in practice is often an excessive commitment to freedom and tolerance, because people fail to realise the subtle long-term erosions of society that can result.
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7587
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The issue of abortion seems insoluble, because there is nothing with which to compare it [Scruton]
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Full Idea:
The issue of abortion is intractable, partly because of the absence of any other case to which it can be assimilated.
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From:
Roger Scruton (A Dictionary of Political Thought [1982], 'abortion')
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A reaction:
This is the legalistic approach to the problem, which always looks for precedents and comparisons. All problems must hav solutions, though (mustn't they?). The problem, though, is not the value of the foetus, but the unique form of 'ownership'.
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