Consciousness of the arbitrary nature of language, its essential conventionality (in the sense not of conformity, but of operating in accordance with tacitly agreed codes which have no naturally inherent laws) has become a major feature of twentieth-century poetry. It is almost, one is tempted to say, the defining feature of the modern, were it not that post-modern poetry is still more marked by it than classical modernism of the Pound-Eliot-Williams upheaval. By freeing poetry from the demands of consecutive syntax and claiming as its own the modern cinematic technique of juxtaposing images for primarily emotional/dramatic effect, modernism opened the way to further experiments in the breaking down of accepted assumptions governing verbal expression. Once the standard of 'correct', transparent English, whether spoken or, still more significantly, printed, was breached, it became possible to question the conventions of presentation which educated writers and readers had come to take as inviolable rules, and which are still treated as such in the language of scientific, journalistic and critical discourse. It became possible for transgression, or non-observance, of the rules to function on a positively sophisticated, rather than vulgarly negative, level — though this, of course, also presupposes general familiarity and conformity with them, since the abnormal effects of dispensing with them, or operating them in unfamiliar ways, depends on the existence of a strong feeling for them as the linguistic norm.