I had a teacher once ask that question during a particularly challenging Yoga class, back in New York. We were all bent into these exhausting sideways triangles, and the teacher was making us hold the position longer than any of us would have liked.

"Why do we practice Yoga?" he asked again. "Is it so we can become a little bendier than our neighbors? Or is there perhaps some higher purpose?"

Yoga, in Sanskrit, can be translated as "union." It originally comes from the root word yuj, which means "to yoke," to attach yourself to a task at hand with ox-like discipline. And the task at hand in Yoga is to find union--between mind and body, between the individual and her God, between our thoughts and the source of our thoughts, between teacher and student, and even between ourselves and our sometimes hard-to-bend neighbors. In the West, we've mainly come to know Yoga through its now-famous pretzel-like exercises for the body, but this is only Hatha Yoga, one limb of the philosophy. The ancients developed these physical stretches not for personal fitness, but to loosen up their muscles and minds in order to prepare them for meditation. It is difficult to sit in stillness for many hours, after all, if your hip is aching, keeping you from contemplating your intrinsic divinity because you are too busy contemplating, "Wow . . . my hip really aches."

But Yoga can also mean trying to find God through meditation, through scholarly study, through the practice of silence, through devotional service or through mantra--the repetition of sacred words in Sanskrit. While some of these practices tend to look rather Hindu in their derivation, Yoga is not synonymous with Hinduism, nor are all Hindus Yogis. True Yoga neither competes with nor precludes any other religion. You may use your Yoga--your disciplined practices of sacred union--to get closer to Krishna, Jesus, Muhammad, Buddha or Yahweh. During my time at the Ashram, I met devotees who identified themselves as practicing Christians, Jews, Buddhists, Hindus and even Muslims. I have met others who would rather not talk about their religious affiliation at all, for which, in this contentious world, you can hardly blame them.

The Yogic path is about disentangling the built-in glitches of the human condition, which I'm going to over-simply define here as the heartbreaking inability to sustain contentment. Different schools of thought over the centuries have found different explanations for man's apparently inherently flawed state. Taoists call it imbalance, Buddism calls it ignorance, Islam blames our misery on rebellion against God, and the Judeo-Christian tradition attributes all our suffering to original sin. Freudians say that unhappiness is the inevitable result of the clash between our natural drives and civilization's needs. (As my friend Deborah the psychologist explains it: "Desire is the design flaw.") The Yogis, however, say that human discontentment is a simple case of mistaken identity. We're miserable because we think that we are mere individuals, alone with our fears and flaws and resentments and mortality. We wrongly believe that our limited little egos constitute our whole entire nature. We have failed to recognize our deeper divine character. We don't realize that, somewhere within us all, there does exist a supreme Self who is eternally at peace. That supreme Self is our true identity, universal and divine. Before you realize this truth, say the Yogis, you will always be in despair, a notion nicely expressed in this exasperated line from the Greek stoic philosopher Epictetus: "You bear God within you, poor wretch, and know it not."

Yoga is the effort to experience one's divinity personally and then to hold on to that experience forever. Yoga is about self-mastery and the dedicated effort to haul your attention away from your endless brooding over the past and your nonstop worrying about the future so that you can seek, instead, a place of eternal presence from which you may regard yourself and your surroundings with poise. Only from that point of even-mindedness will the true nature of the world (and yourself) be revealed to you. True Yogis, from their seat of equipoise, see all this world as an equal manifestation of God's creative energy--men, women, children, turnips, bedbugs, coral: it's all God in disguise. But the Yogis believe a human life is a very special opportunity, because only in a human form and only with a human mind can God-realization ever occur. The turnips, the bedbugs, the coral--they never get a chance to find out who they really are. But we do have that chance.

"Our whole business therefore in this life," wrote Saint Augustine, rather Yogically, "is to restore to health the eye of the heart whereby God may be seen."

Like all great philosophical ideas, this one is simple to understand but virtually impossible to imbibe. OK--so we are all one, and divinity abides within us all equally. No problem. Understood. But now try living from that place. Try putting that understanding into practice twenty-four hours a day. It's not so easy. Which is why in India it is considered a given that ............