I wrestle with a sentence I have yet to complete. This act of completing, the precise act of wrestling.
Like a moon in its halved phase, I know its full shape is already out there, only I can't see its other half yet.
From The Art of Fielding by Chad Harbach:
It was easy enough to write a sentence, but if you were going to create a work of art, the way Melville had, each sentence needed to fit perfectly with the one that preceded it, and the unwritten one that would follow. And each of those sentences needed to square with the ones on either side, so that three became five and five became seven, seven became nine, and whichever sentence he was writing became the slender fulcrum on which the whole precarious edifice depended. That sentence could contain anything, anything, and so it promised the kind of absolute freedom that, to Affenlight's mind, belonged to the artist and the artist alone. And yet that sentence was also beholden to the book's very first one, and its last unwritten one, and every sentence in between. Every phrase, every word, exhausted him.