The Pop Quiz Paradox

The JTB View: S knows that P if and only if

i. S is justified in believing that P,ii. P is true, andiii. S believes that P.

The person who will get the job has 10

coins in his pocket.

The Revised View: S knows that P if and only if

i. S is justified in believing that P,ii. P is true, iii. S believes that P, andiv. ???

The First Proposal: S knows that P if and only if

i. S is justified in believing that P,ii. P is true, iii. S believes that P, andiv. S is certain that P.

The Second Proposal: S knows that P if and only if

i. S is justified in believing that P,ii. P is true, iii. S believes that P, andiv. S’s justification for P does not include any falsehoods.

An inferential belief is a belief that is a belief that is based on other beliefs.A non-inferential (or basic) belief is one that is not based on other beliefs.

A defeater for S’s belief that p is something such that, were S to find out about it, she should no longer believe that p.

The Third Proposal: S knows that P if and only if

i. S is justified in believing that P,ii. P is true, iii. S believes that P, andiv. there is no defeater for S’s belief that P.

A pop quiz is a quiz such that you (the student) won’t know is going to happen on a specific day until that day comes.

The Pop Quiz Paradox1) I’m justified in believing that there

will be a pop quiz on Friday.2) I believe there will be a pop quiz on

Friday.3) If (1) and (2) then: If it’s true

there’s going to be a pop quiz given on Friday, then I know it’s going to be given on Friday.

4) I can’t know that.5) There’s not going to be a pop quiz

on Friday.