Best known as the creator of Sherlock Holmes, Sir Arthur Conan Doyle was also one of the most prominent and outspoken advocates of Spiritualism in the early 20th century. Following personal losses, Doyle became deeply committed to the belief that communication with the dead was both real and meaningful, viewing Spiritualism as a source of comfort and moral truth.

He lectured internationally, authored numerous books and essays defending mediumship, and publicly supported figures and phenomena that many contemporaries questioned. Doyle’s unwavering belief placed him at the center of intense debate, illustrating the powerful emotional and cultural impact Spiritualism held—even among those celebrated for logic and reason.