Thoughts becoming words

Does the act of writing clarify one's ideas or obscure them? There would seem to be two points of view on that question, and I side with both of them.

The essayist Logan Pearsall Smith said this, "What things there are to write, if one could only write them! My mind is full of gleaming thought; gay moods and mysterious, moth-like meditations hover in my imagination, fanning their painted wings. But always the rarest, those streaked with azure and the deepest crimson, flutter away beyond my reach."

Virginia Woolf said something similar in fewer words: "No book is born entire and  uncrippled as it was conceived."

I can recall hearing the novelist Ann Patchett say that no matter how hard she tries, the words she puts down on a page never quite equal the vision she had in her mind.

I know this can be true, for I have experienced it myself. Yet more often I have experienced just the opposite, where the words that come out are much grander than the thoughts that inspired them. Where, I wonder,  did that come from? I don't remember thinking that, but there it is.

Samuel Butler wrote, "Books want to be born: I never make them. They come to me and insist on being written, and on being such and such."

And E.M. Forster famously said, "How do I know what I think till I see what I say?" Exactly. Writing clarifies one's thoughts, except of course when it doesn't.