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Single Idea 19546

[filed under theme 13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / c. Knowledge closure ]

Full Idea

A way of knowing there are cookies in the jar - visual perception - is not a way of knowing what one knows to be implied by this - that visual appearances are not misleading.

Gist of Idea

Knowing by visual perception is not the same as knowing by implication

Source

Fred Dretske (The Case against Closure (and reply) [2005], p.29)

Book Ref

'Contemporary Debates in Epistemology (2nd ed)', ed/tr. Steup/Turri/Sosa [Wiley Blackwell 2014], p.29

A Reaction

Why is the 'way of knowing' relevant? Isn't the only question that of whether implication of a truth is in infallible route to a truth (modus ponens)? If you know THAT it is true, then you must believe it, and implication is top quality justification. No?

The 18 ideas from Fred Dretske

19544 Closure says if you know P, and also know P implies Q, then you must know Q [Dretske]
19545 We needn't regret the implications of our regrets; regretting drinking too much implies the past is real [Dretske]
19547 Reasons for believing P may not transmit to its implication, Q [Dretske]
19546 Knowing by visual perception is not the same as knowing by implication [Dretske]
19548 The only way to preserve our homely truths is to abandon closure [Dretske]
19549 P may imply Q, but evidence for P doesn't imply evidence for Q, so closure fails [Dretske]
19550 We know past events by memory, but we don't know the past is real (an implication) by memory [Dretske]
6445 You have knowledge if you can rule out all the relevant alternatives to what you believe [Dretske, by DeRose]
5801 A mouse hearing a piano played does not believe it, because it lacks concepts and understanding [Dretske]
5802 Representations are in the head, but their content is not, as stories don't exist in their books [Dretske]
5805 Introspection does not involve looking inwards [Dretske]
5803 In a representational theory of mind, introspection is displaced perception [Dretske]
5804 A representational theory of the mind is an externalist theory of the mind [Dretske]
5806 Belief is the power of metarepresentation [Dretske]
5807 Introspection is the same as the experience one is introspecting [Dretske]
5808 Qualia are just the properties objects are represented as having [Dretske]
5809 Some activities are performed better without consciousness of them [Dretske]
5800 All mental facts are representation, which consists of informational functions [Dretske]