In a sense, Rebecca Goldstein – author of “Betraying Spinoza” – has spent her life committing acts of betrayal. She betrayed her Orthodox Jewish background by choosing to study philosophy. Early in her philosophical career, she turned away from her field and broke the unspoken rules of academia by writing a popular novel, “The Mind-Body Problem.” She went on to write five more books of fiction while continuing to teach. Now, with “Betraying Spinoza” and previously with “Incompleteness: The Proof and Paradox of Kurt Godel,” she has returned to writing about philosophy. In an interview with The New York Sun, she described the boundaries of fiction and philosophy – and what it’s like to cross them.

Q: What drew you to philosophy?

A: What was so liberating for me was the nature of doubt. In the culture into which I was born, doubt was seen as a moral failing. In philoso phy, it’s a methodology. It has a positive moral value, and to accept something whole-heartedly, without doubt – that’s seen as a failing.

Then, having studied philosophy, what led you to fiction?

I concentrated in philosophy – mostly philosophy of science and philosophy of math. But I always loved novels, even though I was a little embarrassed about it.When I was finished with my doctorate, I bingeread these highly caloric, 19th-century novels. I never thought I would write one, but in some sense I was preparing. There was something that they fed in me.

What is it like to participate in these two vastly different fields?

It makes me an outsider in both, which isn’t so pleasant. I know that [writing “The Mind-Body Problem”] harmed my philosophical career. It was just not what you’re supposed to do as a young assistant professor hell-bent on tenure.

How did writing fiction change your relationship to philosophy?

It was hard for me to go back to writing philosophy. The thought that I would churn out a paper that anybody could churn out didn’t appeal to me. The liberating thing about writing fiction was voice. I could experiment with different voices. You can’t do that in academic writing.

What led you to write “The Mind-Body Problem”?

I was already an assistant professor of philosophy at Barnard, and I had gone through a very emotionally demanding year. I had had my first child, and I had lost my father, and I started turning my doubt onto the field of philosophy. I was 26. I had my doctorate. I was a professional philosopher. But it didn’t seem to me that I knew more than any other 26-year old when it came to things like grieving for a beloved parent or bringing up a child. I began to think: What is philosophy all about? I couldn’t write a philosophy paper about that, so I found myself writing this novel.

And “Betraying Spinoza”?

I was approached by Jonathan Rosen [the general editor of the Jewish Encounters series]. The conversations we had were superb. We don’t really agree on things, but it was fun. He’s a wonderful antagonist to have. He’s somewhat horrified by Spinoza, and I love him.

Why is he horrified by Spinoza?

Spinoza, in asking us to be consistently, rigorously, ruthlessly rational, asks us to give up a lot of what it means to be human – our passionate ties to other people. He doesn’t ask us to give up passion, but it should be passion for the truth and for objectivity. And he also asks us to give up a passionate attachment to one’s own personal history, the history of one’s people. He’s the first really secular Jew, and I would argue that he really prefigures the Enlightenment.

You’ve written that philosophy attempts to take an objective view of the world, while fiction lets us into subjective views. Do you take the side of fiction?

Yes. I believe that the imagination – and the kind of infiltrating into another worldview that we do in fiction – has a truth of its own. It can’t be gotten at through the purely objective point of view. Of course, you could say that whatever can’t be captured in the purely objective point of view is illusion and doesn’t exist. That is Spinoza’s way. At the end of the book, I try to inhabit him as a fiction writer – warning that this is the trick of a fiction writer. I know that it will make some philosophers very,very angry. But, yes, I believe that there is great value in the imaginative grasp of others’ subjectivity.

Martha Nussbaum has made some similar arguments about the moral value of literature.

I like her discussion of Plato. I’ve heard her work denigrated by philosophers, because it’s very imaginative. She’s trying to imagine what Plato might have been like when he was writing the Phaedrus, and why he would depart so dramatically from his views on love in the middle dialogues. He was in love, she said, and she tried speculating about whom it might be and trying to find a story behind it. She’s showing something that I respect and that I tried to do with Spinoza: Philosophy isn’t just this academic game.You do it with your whole soul.