Kenneth Clark (1903-1983), Another Part of the Wood: A Self-Portrait
(London: John Murray, 1974; rpt. 1976), p. 172:
Logan [Pearsall Smith] had given me a piece of advice, unexpected from him. "If you feel that your pen is running away with you, let it run". I had been brought up on the opposite principle ('Easy writing makes hard reading', etc.) but I have learned from experience that Logan was right. If words come tumbling out it gives to one's style an energy and a rhythm that cannot be achieved by deliberation, and one can enjoy the pleasures of polishing later.