Historian Manning Clark, whose "History of Australia" cites extensively from his studies of Deakin's private diaries in the National Library of Australia, wrote: "By reading the world's scriptures and mystics a deep peace had settled far inside : now he felt a 'serenity at the core of my heart.' He wanted to know whether participation in the world's affairs would disturb that serenity... he was tormented by the thought that the emptiness of the man within corresponded with the emptiness of society at large where Mammon had found a new demesne to infest."