The extravagant manipulation of narrative strategies, the construction of vivid semantic images and the tactics of displacement do not necessarily preclude the unfolding of more or less linear stories – as the novels of Vladimir Nabokov, John Barth and even Thomas Pynchon testify. But they do make it difficult to study them narratologically. The famous narrative theories of Vladimir Propp and A. Greimas were founded on oral literature, or else on fairly primitive forms of written literature, like the folk-tale. 21 The texts they dealt with bore few traces of individual enunciation; this made it much easier to discriminate the story per se. But what has been found is that such theories are of little use with modernist and post-modernist texts, because they cannot take the mode of enunciation into proper consideration.