The phrase "stretch of discourse" is correct and usable in written English
You can use it when you are referring to a passage of spoken or written communication, typically one that is lengthy or considered difficult. For example: "The writer's dense stretch of discourse was difficult to understand."
It also recognizes that communication depends on more than merely objective truth and formal validity, and offers an account of what motivates the assent of the human knower to any given stretch of discourse.
Throughout the interviews, the participants focused primarily on precise understanding of specific information in the text as opposed to grasping main ideas of a long stretch of discourse or synthesizing ideas within a text or across different texts.
According to the Alexandrian version of the theory, a stretch of discourse was to be analysed according to the context in which it was found: in poetry, one expected to find false and impossible statements, in demonstration, necessary and true statements.
However, a closer look at their use in larger stretches of discourse and in conversational contexts reveals several functions other than restricting the scope of the proposition.
A further goal is to make this complex analysis as practicable as possible, allowing rapid analysis of extended stretches of discourse.
One might take his project, and that of later medieval logic in general, to be a matter of specifying how the introduction of complexity into the individual terms in a categorical statement affects the sense of the whole statement, so that one can deal logically with the complex terms that must be introduced to apply Aristotelian logic to more interesting stretches of discourse.
The paper concludes by illustrating a combined analysis of a stretch of classroom discourse.
The debate about academic writing has given rise to new terminology: "old literacy" refers to more traditional forms of discourse and training; "new literacy" stretches from the blog and tweet to multimedia presentation with PowerPoint and audio essay.
Then stir it all up with a lot of discourse, and of discourse about discourse.
"It's full of discourse and ideas.
I prefer more austere forms of discourse".
