forum 2: week of 16 Jan - Lewis

Fragment of a discussion from Course talk:Phil440A

I also feel unsure about Lewis' rule of conservatism. From what I understood it sounded like this rule allows one to properly ignore certain possibilities if others commonly ignore it as well. It might be a misunderstanding of this rule on my part, but this seems to weaken and if not undermine some of Lewis' other rules. If one allows common knowledge to guide their reasoning then it seems that it would just leave one with assumptions, rather than any true knowledge. Lewis mentioned how the rule of conservatism can be derived from other rules and vice versa, but I was unclear of whether this rule could stand on it's own when properly ignoring a possibility.

Andreaobrien23:37, 19 January 2012