Dialectica 66 (3):375-410 (2012)

Elia Zardini
Universidade de Lisboa
The paper discusses some ways in which vagueness and its phenomena may be thought to impose certain limits on our knowledge and, more specifically, may be thought to bear on the traditional philosophical idea that certain domains of facts are luminous, i.e., roughly, fully open to our view. The discussion focuses on a very influential argument to the effect that almost no such interesting domains exist. Many commentators have felt that the vagueness unavoidably inherent in the description of the facts that are best candidates for being luminous plays an illicit role in such argument. The paper centres around the idea that vagueness brings with itself the prima facie plausibility of soritical principles. Using the diagnostics of sharpenings, it is first pointed out that, despite certain considerations to the contrary, the margin‐for‐error principle required by the anti‐luminosity argument may well derive all of its plausibility from an underlying soritical principle. The notion of confidence that is relevant to the argument is then isolated and sharply distinguished from the notion of subjective probability. Against this background, it is argued that the reasoning about confidence involved in the argument in favour of the problematic margin‐for‐error principle is fallacious in the same way in which sorites reasoning is. This reveals the possibility of having reliable knowledge even at the penumbral limit with falsity, a possibility for which a concrete formal model is constructed. The model in turn permits a deeper appreciation of the role played in the dialectic by the distinction between confidence and subjective probability as well as by confidence requirements on knowledge. It is concluded that careful heeding of vagueness and its phenomena, far from forcing new and surprising limits on our knowledge, actually removes one of the main barriers – unreliability – often thought to stand in its way.
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DOI 10.1111/dltc.2012.66.issue-3
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References found in this work BETA

Knowledge and its Limits.Timothy Williamson - 2000 - Tijdschrift Voor Filosofie 64 (1):200-201.
Vagueness, Truth and Logic.Kit Fine - 1975 - Synthese 30 (3-4):265-300.
Luminosity Regained.Selim Berker - 2008 - Philosophers' Imprint 8:1-22.
Knowledge: By Examples.Colin Radford - 1966 - Analysis 27 (1):1.
A Model of Tolerance.Elia Zardini - 2008 - Studia Logica 90 (3):337-368.

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Citations of this work BETA

The Structure of Justification.Sven Rosenkranz - 2018 - Mind 127 (506):629-629.
A New Puzzle About Belief and Credence.Andrew Moon - 2019 - Canadian Journal of Philosophy 49 (2):272-291.
Some Problems with the Anti‐Luminosity‐Argument.Wim Vanrie - 2020 - Pacific Philosophical Quarterly 101 (3):538-559.

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