'Flaubert is categorical: poetry is a silent adventure of the soul, a lived event that has nothing in common with language; more precisely, poetry takes place against language.'
Initiatially puzzled by this. Possible interpretation = poetry disturbs language, from the inside, like a wind disturbing grass or making a curtain flutter. It, poetry, is visible, like the wind, only in and through what it disrupts and displaces. Poetry, in this sense, is a kind of force of silence inside language itself - ruffling its surface, upsetting syntactical fluency, breaking up frozen metaphors...
Alternatively, Sartre thinks that for Flaubert language is always a kind of foreign substance introduced into one's being, eccentric to the haeccity of the self, a socially defined material imposed on the tender soul. The silence of poetry is the rebellion of this mute soul against the foreign power which has invaded and colonised it. The affirmation of the silence within language and against language is the affirmation of what can not be assimilated to this foreign body introduced into our souls. The soul is only visible in the warp or anamorphosis it introduces into the symbolic order of language. The soul is no more than this anamophosis.