When we allow ourselves to move far away from the center, we experience the pain and bitterness that the Buddha described in his First Noble Truth. The cause of that distress, he said, is attachment. A Zen practitioner can feel anger, sorrow, or physical pain just as he can experience joy and laughter. But once his immediate response to the situation is over, he does not carry it with him. He puts it down. He knows the consequences of remaining attached to it. As the response impulse slips away, he returns to a state of equilibrium.

A friend of mine, a photographer, asked if I'd like to go with him to the zoo. He was going to take some pictures and he wanted some company and someone he trusted to watch his equipment while he was climbing around, getting the tough shots. It was a beautiful fall morning and I welcomed the change of routine.

We arrived shortly after the zoo opened, and as we entered, a woman from the magazine he was taking pictures for unexpectedly approached us. She had made some last minute changes and wanted to show him exactly which pictures she wanted. Since they were discussing business, I walked away to let them talk. A young mother with three children, one child in a stroller and two older boys, caught my attention. The boys were typical boys... picking on each other, running around wildly, oblivious to everything around them. I admired the patient way the mother was trying to control them.

My friend and the woman from the magazine began to walk towards the animal exhibits. I tagged along while they talked. We stopped near a fountain and pool, deciding which animals he would photograph first. He placed his camera bag on the seating-ledge of the pool and began to load film when from out of nowhere came the two boys. They ran into the woman, nearly knocking her into the pool. My friend wasn't so lucky. His camera flipped out of his hands and landed in the water. The boys' mother ran to catch up with them and though she apologized profusely, the woman from the magazine was vicious, castigating her for not raising her "brats" properly, for inflicting "wild animals" on civilized people, for not using birth control. My friend - the only one who had really sustained any damage in the encounter - tried to pacify her, but she would not be calmed. He took her arm and gently pulled her away, while she turned and shouted one last insult at the young mother. "Get your tubes tied... or keep your legs closed!"

I took a deep breath and looked with sympathy at the young woman whose eyes were brimming over with tears. "Is your boy all right?" I asked her. She shook her head affirmatively. I smiled, wishing I could do more. "She's having a bad day, I guess," I said by way of apologizing for the older woman's rudeness. Then my friend called me, asking me to hold his camera bag while he opened the wet camera, checked it, and took a spare camera from the bag. As he loaded film in it, he directed the conversation back to the animals, in particular those in the nearby Primate House. I didn't know what he had said to her. But I did know it wasn't my place to interfere in his business relationship. This woman was his client. Photography was his business. He was accomplished enough in Zen to know how to handle such an awkward situation.

The woman's attention was suddenly on an orangutan that was eating an onion. She began cursing the mother and the boys. "We're gonna miss that shot because of those freaks," she hissed. Then she turned to my friend and without trying to conceal her irritation said, "By the time you get set up that onion will be gone!"

Still meticulously tending his equipment, he said calmly, "Then we'll get him a carrot." Fortunately the orangutan wasn't exactly wolfing the onion down... he was actually slowly peeling it. My friend got half a dozen shots.

The woman was still angry. Her attitude had completely changed from the way it had been before the encounter with the boys.

We walked through the various animal exhibits at a slow pace; and as we turned one corner, we saw the boys throwing sticks at a peacock. "Oh my God!" the woman growled. "Why doesn't somebody throw that stupid bitch and her brats out of here!" The peacock easily moved out of the way of the sticks, and the mother scolded the boys, as any mother would. But the woman with us remained agitated.

The zoo was a big place, covering many acres. When the woman went to the ladies' room, my friend apologized. "I didn't know she'd be here," he said, "or that she'd be so traumatized by a little run-in with kids. I feel guilty for not telling you to take off. But the fact is I'm glad you're here." He shook his head, "She goes over the edge and doesn't come back!"

How far over the edge she had gone became clear when we came to the Penguin exhibit. Penguins are always fun to watch. They can not only swim as well as any fish, but also have an amazing ability to hop and jump. As the feeder threw out fish, penguins churned the water in a feeding frenzy. Some would jump up onto a rock to await the keeper's sardine-toss, while others would swim in crazy zigzag patterns just below the surface of the water, hoping to be in the right place at the right time to get a fish. Their antics were hilarious and I was grateful for the comic relief. Suddenly the boys ran up to see the feeding show and I braced myself for what was coming. The woman shouted at the mother, "Put a leash on those wild animals if you can't control them!" The young mother burst into tears and sobbed, "I'm doing the best I can."

That did it. My friend stopped photographing the penguins and said, "I think I've got enough for today. I can come back tomorrow if I need more." He took the camera bag from me and unzipped it. As he finished talking to his client, I saw an ice cream vendor pushing a cart towards us. I signaled him and asked the young mother, "Ok to get the kids some ice cream?" She shook her head; I paid for two popsicles and gave them to the boys.

"That's right!" the client said sarcastically. "Reward them for being bad!"

And with that, having had the day ruined by anger, we left.

We all know the feeling of having our emotions spiral out of control. We get angry at some object, or at someone else, or at ourselves, and then that anger revives other old grievances and we get angrier still. One thing after another piles onto us until the pressure is too great and we implode. And by then, we've lost our ability for calm, rational thinking and acting: we've lost our equanimity and upset our balance. It's not a nice place to be, neither for us, nor for those around us.

But how do we regain control and change back into what we were before we lost our balance? It is so difficult and is, to Zen, a great challenge.

Scientists have discovered that there is an inherent physiological explanation for why we are so resistant to change. Scientific American's Frontiers TV series, hosted by Alan Alda, ran an episode that looked at the functioning of the prefrontal cortex of the brain as it related to learning and behavior modification.

The episode begins by showing us a toddler, a girl of about ten months, as the subject of the experiment. She is shown a small toy, which is then inserted, into one of two holes in a table in front of her so she can clearly see into which hole it was placed. Next, a cloth is placed over each of the two holes and she is asked to find the toy. Without hesitation, she uncovers the correct cloth and removes the toy from inside the hole. The experiment is repeated, but this time the toy is placed in the other hole. The two holes are covered with the cloths and the girl is asked to find the toy. This time, again without hesitation, she looks not where she saw the toy put, but in the hole where the toy was placed the first time. A more complex experiment was performed with a three year-old and, again, it was found that the child acted upon the earliest-learned information and ignored the new information. The child observed the change and should have made a new choice, a correct choice. Instead, the child returned to what it considered the known and normal location. The same experiment, but in a more complex design for adults, was performed on Alan Alda, the show's host. He laughed at himself as he struggled through the test. The result was that his response time slowed considerably when he was confronted with new, different, information on which to base his decisions. It took a lot of extra effort to make the correct decisions.

Even though the prefrontal cortex (frontal lobe) of the brain is fully developed in adults, there is still a struggle of will that must initiate a change in habituated action. Our tendency is to go along with the same response we've always had regardless of changes in the situation that suggested the response in the first place. Resistance to change is programmed in us.

Zen requires an enormous amount of willpower -- perhaps more than any other activity or endeavor -- because it insists that we alter ourselves: our habits, our ways of thinking and reacting to things, to all our conditioned solutions to life's problems. This willful alteration of mind is counter to our nature. In fact, one of the most important aspects of our nature is this natural principle or force that tends to make us resist change.

American physiologist Walter Cannon coined the term "homeostasis" in 1932 as a derivation of homoios, meaning similar, and stasis, meaning state. In its simplest definition, homeostasis is a natural condition of dynamic self-regulation. When something loses its balance, a regulating force tries to restore the original balance. Unfortunately, when powerful positive or negative emotions disturb our equilibrium, our response determines whether we move back toward equilibrium or farther away from it. The farther away from it we go, the deeper into trouble we get.

We usually regain our balance eventually, but how it happens varies: if we let ourselves continue to spiral out of control, we are damaged and in crisis. We become depressed, anxious, or experience complete breakdown. But if we, through sheer force of will, command ourselves to "let go" of the psychic disturbance, we can quickly return to our equilibrium state - and this is where we want to head as we're practicing Zen.

An similar concept was postulated by Isaac Newton in 1687 and was published as The Mathematical Principles of Natural Philosophy. We know it today as his famous laws of motion. Newton's first law states that, essentially, everything remains in equilibrium until a force acts upon it. In other words, equilibrium is the natural state of affairs for things. His second law states that a change in the equilibrium of something is proportional to the force that took it out of equilibrium. And his third law states that anything that has lost its equilibrium applies a counter- force that balances the force that took it out of equilibrium to begin with. Homeostasis, in this context, is the natural tendency of a thing to want to be in equilibrium. It is the foundation for Newton's three laws of motion. But it is also a principle that can apply to the motion/equilibrium of our psyche. In the loosest sense, when we are in equilibrium, we are at peace and when we are not, we're "stressed out." Stress, to the psyche, is like a force applied to an object. If someone yells at us, we yell back. If someone we love dies, we are emotionally devastated. Our psyche is in a constant state of response. At every hour of every day, we are subjected to a variety of forces that disturb us and provoke reactions from us.

Though it seems to be the last thing we want to do or should do, Zen mandates that we resist that imbalance in the first place or, if we find ourselves pulled out of our normal resting place, we employ immediate counter-force to restore balance. We don't wait for time, fatigue, or frustration to help us to creep back to our balance zone. We force ourselves to gain immediate control of ourselves. This sounds easy but it isn't because it is counter to our natural, common sense, reaction.

If a wild fire rages towards us, we start a controllable backfire to rob the inferno of fuel. We want it to burn itself out; but on the surface, our action seems to contradict our purpose.

When we first come to Zen, we are enthusiastic. We are certain we will wear our cushion out. But within a few days we are back in the state we were in before we decided to take up Zen. We cannot change our ways. All our good intentions inexplicably vanish. If we do sit, we easily lapse into forgetfulness, losing count by daydreaming if we're working with the Healing Breath, or bringing so much anxiety to the cushion that we cannot hold our breath for more than a few seconds. We say we want the tranquility of Zen and find ourselves twitching nervously on the cushion. We were calmer before we sat down. We quickly discover that the new routine is not a groove we can settle into; and making a new groove requires more work than we expected, and so our enthusiasm vanishes.

Tranquility is our original natural state, but as our ego develops and then struggles with life's problems, determined to succeed, we find ourselves being drawn away from that center point as we seek to gain material or social goals. There is no tranquility to be found so far away from the center. Eventually we become weary of the turmoil we've worked so hard to experience, and long to regain that center, but by then we have become accustomed to adversity and cannot bring ourselves to change. We balance our lives around turmoil. Only a force of equal power to that which we expended attaching ourselves to worldly objects can push us back to our original center. Usually it takes a catastrophic event; but sometimes it is years of self-destructive behavior that add up to the necessary total. Any force less than this is not adequate; and so we sit and squirm or let our determination fade away.

When we allow ourselves to move so far away from the center, we experience the pain and bitterness that the Buddha described in his First Noble Truth. The cause of that distress, he said, is attachment. A Zen practitioner can feel anger, sorrow, or physical pain just as he can experience joy and laughter. But once his immediate response to the situation is over, he does not carry it with him. He puts it down. He knows the consequences of remaining attached to it. As the response impulse slips away, he returns to a state of equilibrium.

At the Zoo that day, I could see the difference between holding on to anger and letting it go. One woman's persistent anger had destroyed what should have been a pleasant day for all around her.

Motivation is what moves us. We can train ourselves to detach and to look forward to our daily sessions on the cushion. We can achieve equanimity, or as Hsu Yun said, "acquire the poise of a dead man." The task begins by becoming aware of how far our life has strayed from the center and how close we are to the edge.