|Similarity metrics: a measure of similarity. It is a problem in relation to possible worlds that it is not always determinable which one of two worlds is closer in relation to a third.|
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Similarity Metrics/Similarity/Possible Worlds/Nozick: the measure for the next world must be: what if the antecedent is true - E.g. alphabetical order on the shelf: is an explanatory, not merely a representative order. - Why are the things there? Variant: content arranged, but coincidentally the same order - then the alphabetical order is not an explanation. - ((S) Then the neighborhood is no next world, but an irrelevant world.)
Closure/Nearest World/Similarity Metrics/Nozick: when the condition (3) (believe nothing wrong) was to be completed, then, if p implies q, the non-q-situation must not be further away from the actual world than the nearest non-p-world. - (s.u.) - NozickVsClosure under known implication: we do not have to know or believe all the consequences of our knowledge.
Closure/knowledge/Skepticism/Nozick: if our knowledge were closed under known implication, then if p implies q, the non-q-situation must not be further from the actual world than the nearest non possible world. - Problem: when this is a "non-tank" world, then the statement would demand that the world of the skeptic does not exist, that the tank-world is not further away from the actual world, than any other non possible world. - Problem: we would believe p, even if it is wrong, then we do not know that p. - All conditionals, which say that we believe nothing wrong, would be wrong.
Completed: would be the concept of knowledge only if the world of the skeptic might exist, if p were not true. - So when our concept of knowledge would be so strong, skepticism would be right. - Nozick: but we do not have to accept that.
Philosophical Explanations Oxford 1981
The Nature of Rationality 1994