The notion that inspiration is something that happened thousands of years ago, and was then finished and done with. . . the theory that God retired from business at that period and has not been heard from since, is as silly as it is blasphemous.
I think what gets you through a small writing project, is just one burst of inspiration. A book, especially a longer book, it's a different kind of force that pushes you through it. It's a vision of the whole thing.
Even if the being is not entirely purified, varieties of inspirations and powers may come down from above but this may lead to serious errors. Inspirations from above mixing with the impurities from below get all muddled up and the sadhak takes this for an absolute command. Many a sadhak has thus fallen into danger. Therefore, one must particularly lay stress on the purification of the being.
Poets should be law-givers; that is, the boldest lyric inspiration should not chide and insult, but should announce and lead the civil code, and the day's work.