"What is my message? That is what troubles me. I have not got a message. I am not by any means so ardent a Radical or as ardent in anything as I was. I have read so many newspapers on both sides that my old views have become so greatly modified that I no longer feel certain of anything. That is too strong, but it is true to a certain extent. Facts and existing circumstances prevent me being so enthusiastic as some are about remodelling the Universe."