Although medieval artes poetriae authors, because of their grammatical and versificatory orientation and the importance they attributed to elocutio, paid less attention to the parts of speech than the attention paid by authors of artes praedicandi or artes dictaminis, however, they did not neglect the dispositive aspects of literary discourse, and strengthened the textual character that began to dominate in Poetics under the dominance of Rhetoric. Although dispositio was not a part of grammar instruction in the XIII century – heir to the grammatical concept of Quintilian –, nevertheless, as a result of the rhetoricalisation process undergone by medieval poetry, other medieval artes poetriae, following in the footsteps of Horace’s Ars poetica, paid great attention to the operative organisation of literary text. Despite the familiarity with classical rhetorical treatises, when medieval poetry scholars dealt with the various ways to start a poem, they did not make use of these sources, as these were written having the forensic oratory as a model, and concentrated their study on techniques that make the defence of legal causes effective, developing the doctrine of exordium to present the case to the receiver and get the favourable disposition of the auditorium. We will pay attention to the sources of artes poetriae in the binomial ordo naturalis/ordo artificialis doctrine and we will analyse the consolidation that textual construction receives in Poetria nova. In this work Geoffrey of Vinsauf provides an extensive treatment on dispositio and the procedures to move from the objective and actual order, which follows the road of nature – ordo naturalis – to the poetic order – ordo artificialis. This distinction will have a great influence on the structure of narrative material. This study provides interesting data about the importance of the structure of literary texts in medieval times and provides a solid theoretical framework to understand the structure of the literary text and thus of textual linguistics.