You must squeeze out of yourself every sensation, every thought, every image, - mercilessly, without reserve and without remorse: you must search the darkest corners of your heart, the most remote recesses of your brain, - you must search them for the image, for the glamour, for the right expression. And you must do it sincerely, at any cost: you must do it so that at the end of your day's work you should feel exhausted, emptied of every sensation and every thought, with a blank mind and an aching heart, with the notion that there is nothing, - nothing left in you.