Sherlock Holmes may have been the epitome of scientific reason, but Arthur Conan Doyle, his creator, was obsessed by seances and spiritualism.

Notebooks describing his earliest contact with mediums and psychic phenomena have emerged this week, 120 years after he wrote them, proving that his interest in seances had started 30 years earlier than previously thought.

The author was working as a doctor in Portsmouth when he attended his first seance in 1887, the year that he published his first Sherlock Holmes story, A Study in Scarlet.

After seeing a medium talking in different voices and a table moving jerkily, apparently tapping out words uttered by the spirits, he wrote of witnessing “a new revelation” to the human race in which religion had become a “real thing” and not merely “a matter of faith”. The contents of the notebooks, which date from 1885 to 1889, are disclosed in a new biography, Conan Doyle: The Man Who Created Sherlock Holmes, by Andrew Lycett.

Mr Lycett said: “He had an interest in the paranormal from an early age, but the detail of his actual dabbling in seances had not been known. He didn’t come out as spiritualist until the First World War. What is interesting about this is that it shows him engaging with spiritualism at an earlier age than that.

“These notes helped me understand what I consider the central enigma of his life – how a trained doctor, who created such an epitome of the rational detective, was obsessed by the supernatural – to the point where, after the First World War, he became a leading proponent of spiritualism.”

In contrast, Holmes was dismissive of the paranormal. When presented with a case involving possible vampirism in his 1924 story, The Adventure of the Sussex Vampire, the detective jokes: “This agency stands flat-footed upon the ground, and there it must remain. The world is big enough for us. No ghosts need apply.”

Conan Doyle’s private papers had been kept under wraps by his family for many years. But after they were sold at auction at Christie’s in 2004, Mr Lycett tracked down the notebooks to New Jersey, to the home of an eminent cardiologist and Sherlock Holmes enthusiast.

In 1887, Conan Doyle recorded going to a patient’s house in Portsmouth and joining a handful of people sitting nervously around a dining-room table hoping to make contact with the spirit world.

For half an hour, they waited without anything happening until the table began to move jerkily, tapping out the words – in a basic kind of Morse code – “You are going too slowly; how long are you going to take?” At the next session, a few days later, the room temperature plummeted, Conan Doyle noted, and one of the women “became icy cold and experienced a sensation as of soft hands patting her upon the palm with a strong feeling that someone was standing behind her”. He continued: “At the command of the spirits we discontinued the sitting.”

Conan Doyle, with his Jesuit education, had struggled to distance himself from orthodox religion, and could never shake off the attraction of the supernatural. Even before attending his first seance, he was peppering stories with paranormal references.

According to Mr Lycett, the experience of seances freed him from his doubts. “He regarded spiritualism as a science or, at least, a natural extension of science.”

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