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People blame philosopher René Descartes for the modern idea that spirit and body are two separate and antagonistic entities. I don't. I think making this division is an age-old trap. It takes work to see clearly that you need your physical senses to be a spiritual person, and that you need a spiritual acceptance of life's goodness to be profoundly sensual and sexual.

When you finally get body and spirit together—Renaissance writers said you need to be a person of soul to do this—you will discover greater joy in lovemaking. It makes sense: If you are a whole person made up of body, soul, and spirit,when you make love with only your body, you're getting only one third of the sex. Spirit and soul like sex, too, and they add immensely to the pleasure.

It disturbs me to meet so many people for whom sex and spirituality are completely unrelated—or exist as opposites. For those who were brought up in a world where religious influence was nonexistent or plain ineffective, it may be a novel idea to consider that sex can be spiritual. Others, like me, grew up in a war between spirituality and sensuality. In my loving Catholic family, the word "sex" could stop conversations and make everyone freeze in embarrassment. I spent my teen years as a monk and seminarian. I didn't have sex until I was in my late twenties.

Yet, despite all of this neurotic baggage, I came to enjoy sex as much as I am captivated by spirituality.

In the monastery, I was taught to see spirituality as part of religion. But my later studies opened up a much larger notion.

I discovered from Renaissance authors that any attempt to transcend yourself can be spiritual. You might learn, think, write, converse— all representing the intellectual side of the spiritual. You might play sports and try hard to reach impossible goals. In a stadium full of adoring, out-of-their-skins spectators, you might make a "miracle" play. Sports can be highly spiritual, to the point where athletes sometimes behave like monks, with their austere lives and diets and schedules. Travel, too, can be a form of spirituality, a way of expanding your world. The most ordinary journey, even just to the other side of town, can be a pilgrimage.

Researching Greek polytheistic religion also had a strong impact on my views on sex. I discovered that people could imagine their god as being extremely erotic, sensual, and even sexy. Aphrodite was a real deity—worshiped, prayed to, revered. In graduate school I studied this goddess closely, noting the way she was presented in sacred art: taking a bath, slowly disrobing, wearing jewelry, holding a mirror to her face.