When I write I must try to capture something in words which for all useful purposes, you might say, can’t be expressed in words. Later it is necessary to translate the words again so that in quite another context they’ll come alive. To be sure, so long as I have a firm grasp on my point of departure, there will always be an inner relationship between the original vision I had and the completed, materialized picture-sequence.
While that original conception must always be in the background, I must not let it become too dictatorial, since, for one thing, I must be prepared to modify it when I switch from writing to directing. For another, my actors, too, have a right – to say nothing of an obligation – to draw straws, to choose among alternatives. The whole process is essentially creative. You write down a melodic line and after that, with the orchestra, you work out the instrumentation.
-Ingmar Bergman [via]