From our former Governor General, a series of fifty (of several thousand) carefully chosen letters he has written to people he has admired and befriended over his seventy-plus years, that sets out David Johnston's frank, informed, and novel thoughts about Canada.      Touching on a wide range of topics ranging from learning, the law, kindness and courage, to the monarchy, Aboriginal education, justice, bilingualism, mental health and hockey, David Johnston has always used the