Reading The Midnight Disease by Alice W. Flaherty. Have just started it, but I was struck by this line: "Beauty drives copies of itself, whether in art, or when we want to make children with someone we love."

She's a writer and medical doctor who has suffered - if that's the word - from hypergraphia and writers' block, and the book is about the biological mechanisms behind both. There are so many ways to come at the question of creativity; this looks like a particularly interesting and analytical essay on the subject ("essay" in the sense of attempt; it's a full length book; and while I'm qualifying, the link above is to Amazon, but they do have the book at the lovely Readings bookshops right here in Melbourne...)