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Single Idea 15284
[filed under theme 14. Science / C. Induction / 5. Paradoxes of Induction / b. Raven paradox
]
Full Idea
The question about Hempel's Paradox is whether contraposition is not only equivalent in truth, but equivalent tout court. It forcibly inserts new predicates into a context of properties known to be connected by nature.
Clarification
A→B so ¬B→¬A is contraposition
Gist of Idea
Contraposition may be equivalent in truth, but not true in nature, because of irrelevant predicates
Source
Harré,R./Madden,E.H. (Causal Powers [1975], 7.I)
Book Ref
Harré,R/Madden,E.H.: 'Causal Powers: A Theory of Natural Necessity' [Blackwell 1975], p.123
A Reaction
[compressed] This seems to capture quite nicely the intuition most people have (which makes it a 'paradox') that the equivalent predicate is irrelevant to the immediate enquiry. The paradox is good because it forces the present explanation.
The
16 ideas
with the same theme
[problem irrelevant evidence for a general law]:
19000
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Read 'all ravens are black' as about ravens, not as about an implication
[Belnap]
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17674
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The raven paradox has three disjuncts, confirmed by confirming any one of them
[Armstrong]
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15889
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It is because ravens are birds that their species and their colour might be connected
[Harré]
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15890
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Non-black non-ravens just aren't part of the presuppositions of 'all ravens are black'
[Harré]
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15284
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Contraposition may be equivalent in truth, but not true in nature, because of irrelevant predicates
[Harré/Madden]
|
15285
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The items put forward by the contraposition belong within different natural clusters
[Harré/Madden]
|
15287
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The possibility that all ravens are black is a law depends on a mechanism producing the blackness
[Harré/Madden]
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16832
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If something in ravens makes them black, it may be essential (definitive of ravens)
[Lipton]
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16836
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My shoes are not white because they lack some black essence of ravens
[Lipton]
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16831
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A theory may explain the blackness of a raven, but say nothing about the whiteness of shoes
[Lipton]
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16833
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We can't turn non-black non-ravens into ravens, to test the theory
[Lipton]
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16834
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To pick a suitable contrast to ravens, we need a hypothesis about their genes
[Lipton]
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18993
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If sentences point to different evidence, they must have different subject-matter
[Yablo]
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19003
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Most people say nonblack nonravens do confirm 'all ravens are black', but only a tiny bit
[Yablo]
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4782
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'All x are y' is equivalent to 'all non-y are non-x', so observing paper is white confirms 'ravens are black'
[Mautner, by PG]
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7006
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Observing irrelevant items supports both 'all x are y' and 'all x are non-y', revealing its absurdity
[Schofield,J]
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