Digression (parekbasis in greek, egressio, digressio and excursion in latin) is a section of a composition or speech that is an intentional change of subject. In Classical rhetoric since Corax of Syracuse, especially in Institutio Oratoria of Quintilian, the digression was a regular part of any oration or composition. (An oratorical discourse should have five sections: prelude, narration, argumentation, digression and conclusion.