from Chapter 3:

The following self-report shows that the feeling of love, as it thrives between young lovers, is a powerful means of slipping through the eye of the needle into the bright world of joyous communion with another person. Monica is a pretty, petite woman in her late thirties. She has lived an active spiritual life for many years and has experienced a variety of meditation states.

I was sitting at the edge of my bed waiting for my lover. As I was thinking about him and how much I loved him and valued his love, I grew determined to just love him that night, to be concentrated in loving rather than allowing myself to be distracted about worries about our future.. . .

My lover arrived shortly after I had made my resolution, and for some reason it was not difficult at all to focus on that feeling of love. As we were making love, I remember looking into his eyes and being "undone" by the love and naked vulnerability I saw in them:

All of a sudden I felt no separation between us. I was startled by that and wanted to draw back. But realizing that I was cutting myself off from him and the love that we were feeling for each other, I continued to look into his eyes and to simply be present with him.

I "fell" into the fullness that had arisen in and between us. It was so uncomplicated and natural, and my mind was amazingly calm and quiet. A simple joy! And our love-making wasn't passive either. In fact, it got rather boisterous and passionate.

I have had the experience of losing myself a few times in meditation, but this was the only time it happened during lovemaking. That day I was undoubtedly emotionally more open than usual, but also his depth of feeling seemed to draw me into a deeper feeling. Afterward he asked me whether I had noticed anything different and nodded in agreement when I told him what I had felt. He said that for him it was as if we had been encased in a large bubble of energy.

The bubble of energy experienced by Monica's lover probably represents a far more common experience than is assumed.

from Chapter 10:

The Secret Circle: A Story Set In India Around 1200 A.D.
They met every fortnight. The house belonged to one of the wealthiest merchants in town. Unbeknown to most people, he also happened to be the guru of the small group that had come together for an important celebration; today, a new member was to be initiated in the Tantric art of sexual union. There were twelve of them--six men and six women, all in their early to late twenties, and perfectly nude. They sat in a circle on a thick carpet. The guru, much older, was seated in the center of the mandala with his own partner, a young girl of exquisite beauty and poise but barely of marriageable age.

The master, an accomplished Tantric adept, had been sitting perfectly still for well over an hour already. . . .His partner, seated on his left, likewise had not stirred for a long time.

This was the third and final day of the puja, or ceremony. Any moment now the master would signal the participants to begin the ultimate ritual. To prepare themselves for this occasion, they had fasted for twenty-four hours, had chanted sacred sounds (mantra) thousands of times, had invoked and made offerings to the deities and protective spirits, had consecrated the room, had meditated for many long hours in the graveyard to overcome fear, had bathed and anointed each other's bodies, had duly honored the guru and his chosen partner, and, not least, had over many years cultivated their ability to retain the breath for prolonged periods so that they could control the movements of the mind.

Earlier in the evening, they had smoked hemp together in a ritual fashion, and then they had participated in the solemn ceremony of consuming the four forbidden substances-wine, fish, meat, and parched grain, all of which were thought to have an aphrodisiacal effect. Men and women alike felt a heightened sensitivity and alertness, which even the heavy fragrance of sandalwood burning in the bowls at the four corners of the room could not dull. The room, which was the group's temple, was charged with an indescribable energy. The space was filled with a vibrancy that exerted a curious pressure on the body and that would certainly have scared unsuspecting visitors. It was almost as if the air were humming with electricity.

At last the master stirred. Thrice he intoned the precious invocation Om rzamah shivaya, "Om, obeisance to the Lord." The signal to begin the final ritual had been given. Careful to avoid any disturbing noises, each man turned to anoint his partner with a reddish paste while muttering holy mantras over her. With great reverence he smeared the paste on her forehead, throat, breasts, abdomen, hands, feet, and, last, the pubic mound. Then each woman did likewise to her partner. Only the guru was not anointed in this manner. His young partner was the new initiate. Thus men and women turned themselves into gods and goddesses for the purposes of the climax of the ritual-sexual congress (maithuna).

Unused to the mounting energy in the room, the guru's partner made involuntary cooing sounds, and even some of the more seasoned celebrants moaned slightly. Again, the guru--now looking utterly transfigured--invoked the Divine. Then he firmly grasped his partner, a virgin, and drew her onto his folded legs. In one swift motion he entered her.

There was no pain, or if there was it was swallowed up by the wave of bliss she felt rippling through her, even as her awareness was instantly lifted out of her body into regions of unspeakable luminosity. The girl's eyes rolled back in ecstasy, and her head flopped backward…