A direct extension of the application of Parry's methods to Old English has been the start of a similar application to Middle English alliterative poetry Versions of the formulaic theory modified to admit some element of writing have multiplied rapidly in recent years. R. E. Diamond thinks that written formulaic poetry is possible but that it is impossible from internal evidence alone to determine whether any given formulaic poem is oral or not. The application of Parry's work to Old and Middle English literature had a considerable — impact on work in these fields. Magoun initiated the introduction of the methods used on Homer and Slavic poetry with analyses of Caedmon's Hymn and a section of Beowulf. The chapter focuses on to make a critical survey of the origins of the formulaic theory, and then discusses some of the chief developments and problems resulting from the application of the theory to Old and Middle English alliterative verse.