From the publisher: Conan Doyle and The Mysterious World of Light traces the spiritualist career of Sir Arthur Conan Doyle between the years 1887 and 1920.
Starting with his early psychic investigations in Southsea, it tracks his development from a fascinated dilettante to becoming the committed advocate of a world movement. Throughout these years, Light, a magazine dedicated to the mystical and occult, traced his journey, not least by the letters and articles he wrote exclusively for the magazine. It was and still is the organ of the London Spiritualist Alliance, now known as the College for Psychic Studies.
Every article and letter Conan Doyle wrote for the magazine during this period is here reproduced, often for the first time, as well as correspondence and articles bearing on his own writings. The book thus tells the story of Conan Doyle's Spiritualism while surrounding his writing with the discussions, debates and controversies of his time.
It sets his belief in the context of his powerful imagination which created the iconic Sherlock Holmes, his indefatigable energy which made him such an effective missionary and all against the backdrop of the Great War, which was a powerful impetus for his public declaration of faith in 1916.
For the question of how the creator of the arch-rationalist Sherlock Holmes also came to believe in ghosts, this book holds the fascinating answers.
The introduction can be found here