 Kroon, though expressing sympathy for Nozick's view that the claim that people know many facts about an independently existing world can be reconciled with the position that people do not know that certain skeptical possibilities do not obtain, questioned whether Nozick had correctly identified how to accomplish this, and suggested that a better way was available.Holt credited Nozick with having "clever things to say about every issue in contemporary philosophy".Walker, discussing Nozick's justification of punishment, questioned his "analogy between revenge and retribution", arguing that it created problems that "raise questions about Nozick's attitude to utility."