forum 4: week of 30 Jan: DeRose on skepticism

I find DeRose's approach quite different from Lewis's; Lewis presents all these rules, whereas DeRose focuses on the idea of sensitivity. DeRose also points out the need to identify the mechanism by which the skeptic at least threatens to raise the standards for knowledge, which is something I did not see in Lewis's approach to contextualism. In spite of these differences, what both approaches have in common is that their use of "knowledge" is ambiguous or arbitrary (to me).