In West of Jesus, Steven Kotler finds the spiritual in surfing.

Would the story about the conductor, a mythical surfer-god "who could control the weather and conduct the waves," have resonated with you if you hadn't been sick with Lyme disease?

Years ago, when I first heard the story I turned it into a short story. Then more recently I was convinced to go surfing when I was so unbelievably sick I was suicidal. I went surfing, and I felt better. Surfing gave me life, so when I heard the conductor myth again, I was reminded of all the stories I had heard about surfing and spirituality. I originally thought it was mumbo-jumbo, but with surfing's effect on my own health, I started drawing some parallels.

One of the parallels is the connection between the mystical and the scientific. How did you make all these advanced scientific ideas, such as the biological and neurochemical traits of religious people, so understandable?

Luckily, I'm not afraid to call brilliant people and say, please explain this to me like I'm four years old. I was also inspired by a piece Charles Pierce wrote about the Hubble telescope. It was the first time I saw science writing that was stylish, compelling and easy to understand.

You refer to a lot of writers. Why?

I've always read other writers and tried to figure out what they are doing. I got attracted to Joan Didion, whom I quote, and the structure of her White Album struck me as a way I could tell my story. I also read lots of Rob Schultheis. In Hidden West, he manages to do the thing I most wanted to do, which is presenting facts in a context—not isolated—so the reader doesn't have to do the assembling in their brain.

Your previous book, a novel, dealt with similar topics to West of Jesus. Which was easier to write?

The novel is about Kabbalah and was written before Madonna's involvement, so all the knowledge was very forbidden. For this book, more people wanted to talk about spirituality and neuroscience because in 1990 George Bush Sr. declared it the Decade of the Brain. The last 15 years has seen a lot of great work done on the neuroscience of spirituality, a topic once considered nonsense.

Has this changed surfing for you?

I'm still not great on big waves, but they don't terrify me anymore. Every time I go surfing now, my brain says, What's gonna happen today? Approaching something you do fairly regularly and feeling anything can happen, that's the best thing ever.