I don't want to give the impression that Prickett is just re-asserting Romantic articles of faith. I'm still working through his thesis, but he seems firmly centered on the paradoxes and difficulties involved. "Poetry" - the act of imagination - through the ages - gets proclaimed as the living Mind itself, granted all authority in every intellectual sphere... or it's shunted aside as either mere feeling, or only the faded remnants of worn-out superstitions (Vico). Fundamentally unserious, in our science-prose world.
In a sense this is the project set out for every poet - to find a productive level, an authentic basis, for meaning-making. Finding what (new) can be said.