Author Q & A: a conversation with the author on the setting and themes of In the Tenth House

Q. Spiritualism and psychiatry seem at first to be very different subjects — how did you come to write about them together?

A. The connections have always been there but I knew little about them until I started researching this book. Many people believe that it's possible to communicate with the dead, but that's considered outside the realm of scientific inquiry or respectability; unlike the idea that you can talk someone out of being insane. In the late 19th century those positions were largely reversed. Pioneers of psychology like William James were willing to consider both as means of investigating the human condition (many dismissed the "talking cure" as dirty-minded and dangerous, with seances being more ethical as well as spiritual.) I wanted to write about this time when the boundaries were thinnest between two things we think of as faith and science.

Q. Psychic phenomena still inspire passionate disagreement today. Did your research make you a believer?

A. 'Are you psychic?' is one of the first questions people ask when they find out I'm an identical twin. I'm not, but I wish I were! I'd also love to see a ghost but never have. No one's ever proven that these phenomena are or aren't real – it's essentially impossible to prove in the negative anyway – but what is proven is that there are, and always have been, a huge number of frauds. The debate is bound to be passionate. Spiritualism and divination are about the afterlife and fate; slightly disguised versions of the big questions, the ones that determine your entire morality. The psychology of belief is fascinating whatever your stance on the paranormal. When I'm feeling complacent about knowing what is and isn't possible, I read a book on quantum physics.

Q. How did you get the idea for this book?

A. For me it always starts with the characters. I could picture two vivid personalities with a great deal in common, but whose views of the world are too antagonistic to coexist. This era and this conflict were the right venue for their story.

Q. What made you choose late Victorian England?

A. It's a looking-glass version of our time. Thankfully, it's no longer fashionable to suggest that the Victorians were just like us — they weren't — but you can't get away from the parallels. They were tackling problems of economic inequality, purpose, and human perfectibility, not to mention fighting terrorism and colonial wars, but doing so from inside a drastically different worldview. It was also a good period for the subjects I wanted to write about: 1896 marked Freud's first lectures in London. It wasn't the heyday of spiritualism or the nadir of psychiatry, but I found the autumn of that year to be an interesting intersection point. One belief system was ascending to respectability and the other fading into the fringe of superstition.

Q. Where did you find your source material and how much of the story is based on real people and events?

A. They're invented characters on a stage as real as I can make it. The historical record has big personalities, as you'd expect from a pivotal time, and countless episodes so bizarre they're hard to deal with in a novel — no one would believe that you didn't make them up. A number of historical figures appear in cameos. But when I want to show a character from the inside as well as the outside, I'm happiest with pure fiction rather than basing him or her on a single individual.

Q. Science plays a large role in your novel; have you ever been tempted to become a scientist?

A. I didn't have to — my identical twin sister is a neuroscientist. My interest in science is expressed in different ways, but I'd be lying if I said that I didn't in some way feel that I'm getting the best of both worlds. There's a fantasy that comes with being a twin, and that's in living two lives. We like to think that the way we are is the only way we could possibly be. At the same time we muse on 'if I'd gone to law school', 'if I'd gone on that blind date, or not missed that train' that life would be very different. I believe in the impact of trivial decisions. A few small changes and I do think I'd have a different career and a different day to day existence. It makes you think about how you define yourself — 'I'm a born scientist' or 'I'm a born writer' — and how arbitrary those markers might be. That's an idea that certainly turns up in IN THE TENTH HOUSE.

Q. The characters are very concerned with free will and destiny — do you feel like you make the decisions in your life?

A. It's perception, isn't it? In the novel, a man of the ruling class and a woman of the underclass would seem to be the actor and the acted-upon. In practice, both move decisively, sometimes with terrible consequences, all the while thinking they have no choice in the matter. I'm the opposite. Perhaps it's more 21st century to want to feel in control of your destiny. One way to deal with the realisation of powerlessness, of course, is to become a novelist, and move imaginary people around like paper dolls.

Q. Which of the characters are you most like, Ambrose the scientist or Lily the psychic?

A. Both have aspects of me. They're non-English Londoners, uneasy conformists, reflexively dishonest — anybody who likes words knows how easy it is to tell people what they want to hear and manipulate without meaning to. You can't force in traits unnatural to a character (if you could, it would be quite fun to wind up your least-liked quirks and fire them off like mechanical toys) but I'm most drawn to problems I have, or can imagine having. I think I'd like to be more like Ambrose. As arrogant as he can be, his optimism and buoyancy would be great fun.