What are Roman Jakobson's main points in "From Linguistics to Poetics"?
Jakobson's main point is that Poetics, a form of interpretation believed by many close readers at the time to be a matter of internal criticism and arts or aesthetic-centered analysis, is actually a scientific approach under the umbrella of Linguistics.
Jakobson first proves this main point by defining poetics as the addressing or evaluating of the "problems of verbal structure." Linguistics, being itself a study of structures, becomes a meta-evaluation of the evaluation of verbal art (or poetics). However, to get into semantics—something that seems rather necessary for a reader of a text written by a staunch linguist—Jakobson concedes the ability for poetics to be defined beyond the verbal and into the visual or aural. To return to his original theme, verbal, oral, and aural all play according to rules; these rules are also linguistic, for they deal with the "language" of signs.
The rest of the work further bears out the single main point by going into a detailed identification of the process and transference of language. As Darwin did with the animals, so Jakobson here does with the idea of conversation (whether verbal or written), classifying different components of the phenomenon into types and reflecting back on that to prove that linguistic analysis of poetics is itself a poetics.
Some of Jakobson's main points about the appropriateness of a linguistic approach of study to poetics are that (1) poetics deals with poetry's verbal structure, not to be confused with the structure of poetry, while linguists is the science of verbal structure, which therefore subsumes poetics; (2) subjective opinion on content, referred to as literary criticism, cannot take the place of objective analysis of verbal and verbal art; (3) literary analysis and linguistic study consist of the two areas of problems, those being synchrony (present incorporation of options) and diachrony (historic development of options); (4) linguistics encompasses the primary focus of ideation but also attends the secondary factor of emotiveness, which is a primary factor in poetics; (5) in linguistic science, language must be investigated in all varieties of its function in order to provide a concise survey of factors in each speech event, and poetics is one of its functions that requires a concise survey of factors; (6) the emotive function of the Addresser is an integral part of linguistic study that is wrongly overlooked by an exclusive emphasis on the cognitive function of the Addresser, and emotiveness is a function of the Addresser in poetics.
In short, Jakobson is attempting to show how a linguistic expert should study poetics.
Poetics, of course, is about verbage and not about the rhyme scheme or makeup of poetic lines. Linguistics, of course, is the science behind that verbage, so poetics and linguistics merge in this way. Further, because linguistics is truly a science of words, literary criticism (or the judgement of a piece of literature as "good" or "bad") has no power here. Instead, what is preferred is objective analysis, not opinion due to the depth of components.
Jakobson delves deeper into linguistics in this text than I have seen in any of his other works. There are further points Jakobson makes in his text, specifically about "synchrony and diachrony" as well as "ideation and emotiveness" and the survey of language in question. In short, it is a perfect read for a person who wants to be well versed in the science of linguistics.