Safety

Abstract

Since knowledge is but sorrow's spy, it is not safe to know. (The Just Italian (Act V, Scene 1) – Sir William Davenant)1 Consider a popular principle about knowledge and its non-risky character: SAFETY Necessarily (if S knows that P, then centered on the world in which S knows that P there is a sphere of nearby worlds, and in each such world in which S believes that P, P is true).2 Now consider a definition of a certain kind of knowledge: WBK ‘S's knowledge that P is world-bound’ = df. (i) S knows that P, (ii) P is true in exactly one world, and (iii) S believes that P in at least one of the other worlds in the sphere of nearby worlds centered on the world in which S knows that P. Here is a defensible thesis: WB∼S If there are any possible cases of world-bound knowledge, then SAFETY is false.