This paper offers a comparative analysis of the pronouns ipse and iste in Old Latin. We aim to explain their differences and similarities as a consequence of partial common origin in Proto-Indo-European (PIE). We examine the distribution of these two pronouns according to various grammatical, semantic, and pragmatic features. The unequal distribution of ipse and iste suggests that these pronouns derive from items that ranked differently on a referential hierarchy. In consideration of cross-linguistic evidence, these results can be interpreted as remnants of an archaic system of marking proximate / obviative arguments.