Moore’s 35-year navy career was as a surveyor. When he retired, he was in command of six surveying vessels. He concluded that as a surveyor, interested in exactness, he was as qualified as anyone to investigate mediumship.

When he wrote a small book titled The Cosmos and the Creeds, Moore, who went by his middle name, attacked the teachings of the churches and expressed doubt as to the reality of a future life. “At the time I thought that such immortality as man possessed lay in the influence his actions, words, or writings had upon those who were his contemporaries, or who came after him; but that he himself, as an individual conscious entity, disappeared forever, not to be recognized again,” he wrote eight years later in his Glimpses of the Next State. But soon after the first book was published, Moore began to have misgivings about his agnosticism, as he had not investigated sources of evidence outside the narrow confines of the churches. He pointed out that his investigation into spiritism was not prompted by any desire for consolation as he had not lost anyone other than his father many years before and was certainly not grieving and wanting to believe. His desire was simply to get at the truth.

Moore first sat with Cyril Husk, a blind medium, in London on November 16, 1904 and witnessed a variety of physical phenomena, including materializations and the direct voice. Moore was aware of the fact that some people thought Husk to be a charlatan, but he had a total of 40 sittings with Husk over several years and concluded that Husk was a genuine medium. While recognizing that there were fraudulent “mediums,” Moore came to realize that many legitimate mediums were written off as frauds because the investigators or sitters did not grasp the production of the phenomena.

The following month, during December 1904, Moore had several sittings with de Witt Hough, a New York materialization medium. After six or seven other materializations had taken place, a deceased relative, whom he called “Iola” for privacy reasons, materialized. “I approached the cabinet,” Moore wrote, “[and] the figure advanced to meet me with outstretched hands; she was trembling excessively, and could utter only a few words. I saw her twice after that through Hough’s mediumship, and communicated with her many times though other psychics in New York and Boston.” At one of the sittings, Iola told Moore that she did not know that she had died until someone cut off a lock of her hair behind her right ear. A relative in Scotland later informed Moore that a lock of hair had indeed been cut off from behind her right ear.

Moore also had a very interesting sitting with Maggie Gaule Reidinger of New York. Before sitting with Reidinger, Moore visited Dr. Minot Savage, another psychical researcher, to discuss the mediumship of Leonora Piper. Savage told Moore of a sitting with Mrs. Piper in which his son communicated, and pointed to a picture of his son hanging in his office. He also gave Moore a letter of introduction to Mrs. Piper. At the sitting later that day, Reidinger mentioned Moore’s visit with Savage and said that Savage’s son was there at the time. “He is beside me now,” Reidinger continued, “and he wishes me to tell his father that he was with him in his study this morning when you called upon him. He says: ‘My father pointed to a picture, and said, “That is my son.” He afterwards showed you another portrait of him. He gave you a letter, or authorized you to use his name, to assist you to obtain an interview with Mrs. Piper. Let me tell you, you will not get that appointment yet, next week, nor the week after, but you will achieve your object before re-crossing the ocean. Will you convey the message to Dr. Savage from his son? You have written to Dr. Hodgson today.” Moore was very much impressed and certain that Mrs. Reidinger did not know his name. He recontacted Savage to confirm that he had not spoken to Mrs. Reidinger to inform her of his visit that night.

“We have not the faintest evidence that the subconscious self can be tapped by a stranger on first meeting,” Moore wrote of the experience. “To believe it can is to believe that a medium can read the motives, character and innermost thoughts of every person he or she passes in the street. Is it not less difficult to accept the fact at once that Maggie Gaule (Reidinger) received her information from spirits present – in this case from Dr. Savage’s son, who had accompanied me to her house? He and I alone knew what had taken place. Dr. Savage himself was not aware that I had written to Dr. Hodgson on that evening.”

After his 1904 United States tour, Moore’s attitude began to change. “To be brief, I found that the deeper I went into the study of spiritism the more apparent it became that, whether he wished it or not, man’s individuality was not extinguished at death,” he explained. “I read books, visited clairvoyants, and attended séances for materialization.” His biggest mistake, he said, was to attempt to persuade others that what he had observed was no delusion. He had invited a number of them to join him in observing proven mediums. “I found that they could not see as I did; count not hear as I heart,” he lamented. “Their minds were unprepared. Some were considerably impressed at the moment, but the next day thought themselves victims of jugglery on the part of the medium or some confederate.”

As he gained experience in observing mediums, Moore noted that hostile minds and negativity on the part of the sitters resulted in no manifestations. “Unbiased, open-minded expectancy, founded on the reports of previous investigators, affords the best chance to psychics and their spirit controls,” he explained. “Passivity is necessary during the actual sitting.” He further concluded that promiscuous séances are a mistake as the vibrations of the sitters do not blend harmoniously. “The best sittings everywhere have been obtained when five or seven sitters, well known to one another, sit with the same psychic once or twice a week for a long time,” he continued. “The cure for fraud is the formation of, say, thirty men and women, bound together by a common desire to learn the truth.”

Moore made three trips to the United States, where he experienced both physical and mental mediumship. Sitting with Joseph B. Jonson of Toledo, Ohio, he witnessed many materializations, including his father and mother. “In these there was no possibility of error,” he wrote, mentioning that his father’s characteristic “Iron Duke” nose stood out and that he saw him in good light. At one séance, he observed as many as 25 spirit forms emerge from the materialization cabinet and was certain that there were no trap doors of any kind in which confederates in costumes could have been admitted. They came in all sizes and shapes. While some of the materialized spirits returned to the cabinet, some did not have the power to make it back and Moore watched them seemingly evaporate or dissolve into the floor.

Although Moore did encounter fraud among mediums, he concluded that much of it was unconscious fraud while the medium is in a trance state. “Suspicion and hostility impress [the medium] instantly; and I think it is not too much to say that, if more than half the circle are suspecting fraud, the company as a whole will get it in some form or another,” he wrote. “Personally, I will never again sit in a circle with any pseudo-scientific investigator or avowed materialist.”

Because he felt that the Society for Psychical Research was too quick to dismiss some mediums as complete frauds or to have anything more to do with them once there was some indication of fraud, Moore divorced himself from the organization and referred to the SPR as the “Society for the Prevention of Research.”

While Moore sat with dozens of gifted mediums, Etta Wriedt of Detroit, Michigan may have been the most gifted. Moore’s third book, The Voices, dealt solely with her mediumship. He visited her in the United States during 1911 and then further observed her during 1912 and 1913 when she visited England. “For my part I can only say that, in her presence, I obtained evidence of the next state of consciousness so clear and so pronounced that the slightest doubt was no longer possible,” he offered. “I left her house in February 1911 in the condition of mind of a man who no longer fosters ‘belief,’ but who knows what is his destiny when the tomb closes over him and his spirit leaves the earth plane.”