 Greco (2009, 2012) and Sosa (2003, 2007, 2020) contend that knowledge is a kind of achievement—intellectual success through ability, for which the knower is creditable. And in general, success through virtue is more valuable than mere success, especially accidental success. So knowledge is more valuable than true belief. Riggs (2009: 342; see also Riggs 1998 &amp; 2002) puts the point succinctly: