 Metaphysical and semantical concerns were important to Russell in his 1905 paper, but epistemological concerns were no less significant. This became particularly clear when he authored his (1910–11) paper “Knowledge by Acquaintance and Knowledge by Description.” In that paper, Russell distinguished between objects that we are directly acquainted with and objects that we only know under a description. So, for example, I might know myself by acquaintance, but I know the tallest man in Iowa only under a description.