The dispute about the relationship of orality and literacy in Irish literature is arguably as old as the literature itself. As Seán Ó Coileáin remarks, the debate

Not only have recent scholars disagreed about almost every aspect of this relationship; but, as Joseph Nagy has demonstrated, medieval texts themselves acknowledge and play upon tensions between the two modes, the one old and pagan, the other new and Christian. Many of the issues in this debate relate directly to those raised in the subsequent chapters of this study; hence the relevance of a comprehensive discussion of them in connection with early oral and literate traditions, which were arguably intertwined from the introduction of a written vernacular into Ireland.

The principal genres under scrutiny are the older narratives and sagas dating from the Old and Middle Irish periods and the late medieval romances in Middle and Early Modern Irish from the twelfth to the seventeenth centuries. The former are principally in prose, though interspersed with verse passages, which are often composed of dialogue; the latter are comprised of prose narratives with incidental poems, as well as a large number of metrical ‘lays’, some of which have survived into recent times in oral tradition.