"On my experience of his later years at least, while he was the greatest administrative genius I have seen he was almost certainly the worst administrator. He could not get on with his fellow administrators... He did not really understand politics, still less politicians, and in his tidy, administrative mind there was not always enough place for human reactions and human frailties... He was a hard master, but he certainly taught one of his research assistants the meaning of work, and the need for a thorough attack on the facts before one jumped into any theories about a subject."