Archive for the ‘Epistemology’ Category

Knowledge and Truth Value Gluts

Monday, January 16th, 2012

The truth condition is embedded in the analysis of propositional knowledge; if S knows that p then p is true.

Whilst a straightforward condition given a classical bivalent system with values true and false, bringing truth value gluts into the picture raises some novel matters.

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Truthlikeness and the Conjunction Fallacy

Friday, December 30th, 2011

Truthlikeness and the Conjunction Fallacy

Skeptical scenarios can happen!

Monday, November 7th, 2011

Gaza Zoo Paints Donkeys to Look Like Zebras. Wow!

Upcoming Talk

Friday, October 28th, 2011

I am giving a talk next Friday at my department’s logic seminar series. Here are the details:

Title: The Logic of Knowledge and the Flow of Information

Abstract: In this talk I cover some work still in development which concerns the notions of information and knowledge as exemplified in Fred Dretske’s ‘Knowledge and The Flow of Information’. In particular, I cover (1) some work on the logic of information flow and (2) the issue of developing an epistemic logic which captures Dretske’s notion of knowledge as a semi-penetrating operator.

Zebra or Mule?

Thursday, October 20th, 2011

Is this a zebra figurine or a mule figurine cleverly disguised to look like a zebra figurine?


zebra_mule

Skepticism and information

Saturday, July 9th, 2011

Skepticism and information

Confirmation Measures and Transmitted Information

Monday, May 30th, 2011

The following Bayesian confirmation measure is associated with John Maynard Keynes, having appeared in his A Treatise on Probability (1921). The degree to which evidence e confirms hypothesis h is given as:


R(h,e) = \text{ln}(\frac{p(h | e)}{p(h)})

Interestingly, this is strongly reminiscent of a subsequent measure found in Shannon information theory. In philosophy literature, this formula can be found in Dretske’s formulation of information transmission derived from Shannon’s work as well as a measure of transmitted information given by Hintikka.

A Gettierised (Russellised) Historical Fact?

Wednesday, May 11th, 2011

I finally dug up my copy of Russell’s Human Knowledge: Its Scope and Limits and located the passage in which he gives the Gettier-like broken clock example (15 years before Gettier’s paper):

It is very easy to give examples of true beliefs that are not knowledge. There is the man who looks at a clock which is not going, though he thinks it is, and who happens to look at it at the moment when it is right; this man acquires a true belief as to the time of day, but cannot be said to have knowledge.

This passage is found in Section ‘D. Knowledge’, at the end of the Chapter ‘Fact, Belief, Truth, and Knowledge’.

Most would agree that this is not a case of knowledge. But how far can we carry this? Take the following example: A famous historical figure (X) dies and a medical staff member in attendance records X’s exact time of death using a clock hanging on the wall. This clock is also broken but happens to be stuck on the actual time, say, 6pm. Now, although the staff member records a fact (a true proposition), they do not actually know that X died at 6pm. Furthermore, by standard Dretskean information-theoretic epistemology, neither are they informed by the clock that X died at 6pm.

If the staff member does not have knowledge of nor are they informed of the time of death, is what they record a piece of information? Can a recorded fact be information or knowledge if the source of that record neither was informed of nor knew the proposition in question? If their record is used in a biographical book on X, can someone who reads this book 100 years later come to know that X died at 6pm?

Supplementing Belief Revision for The Aim of Truthlikeness

Saturday, April 30th, 2011

New little piece I put together: Supplementing Belief Revision for The Aim of Truthlikeness

Respecting Relevance in Belief Change

Tuesday, April 19th, 2011

I recently read a short and interesting article; Respecting Relevance in Belief Change, which is concerned with investigating the extent to which the formal operations of AGM belief change respect criteria of relevance.

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