According to Peter Klein, foundationalism fails because it allows a vicious form of arbitrariness. The present article critically discusses his concept of arbitrariness. It argues that the condition Klein takes to be necessary and sufficient for an epistemic item to be arbitrary is neither necessary nor sufficient. It also argues that Klein's concept of arbitrariness is not a concept of something that is obviously vicious. Even if Klein succeeds in establishing that foundationalism allows what he regards as arbitrariness, this does not yet mean that he confronts it with a sound objection.