Dr. Brian Weiss began his career as a psychiatrist and was well published and well respected by the time he was 35. In 1979, he became chairman of the psychiatry department at the prestigious Mount Sinai Hospital in Miami and was regarded as a star in his field.
Dr. Weiss's life changed forever when he took on a new patient named Catherine. "She was suffering from panic attacks, phobias, fears, nightmares," he says. "She had begun sleeping in a large closet in her apartment because of fear."
After a year of conventional psychiatric treatment with little progress, Dr. Weiss decided to try hypnosis, a therapy he'd used successfully before. Catherine was able to easily recall traumatic memories from her childhood. When he asked Catherine to go to the source of her pain, Dr. Weiss says he was shaken to his core—Catherine regressed back and started talking about living previous lives.
Dr. Weiss says at first he couldn't believe Catherine's story about being a boy in Ukraine in the 1700s was real. "I thought it was imagination or fantasy," he says. "I didn't believe in any of this, and neither did she."
Yet with each new session, Catherine revealed more past lives and indicated that she had lived 86 times. Dr. Weiss says Catherine soon began to heal. "Her memories were so vivid and so emotional, and her symptoms were disappearing. But it still took more from me because I was so stuck in my left brain and didn't believe in any of this."
Dr. Weiss became a believer when Catherine told him about his own family. He says while Catherine was hypnotized she told him she was with his father, who died two years earlier, and that his daughter was named after his father. "This was all true," Dr. Weiss says. "My father's Hebrew name was Avram. He died two years before ... [and] did not have an obituary. There is no place to look this up. And my daughter was named after him."
Dr. Weiss says Catherine also told him she was with his son, who had died a decade before at just three weeks after his birth.
Despite the real professional risks involved, Dr. Weiss wrote about Catherine in the book Many Lives, Many Masters, which is celebrating its 20th anniversary in 2008. "I was chairman of the psychiatry department. I had tenure. I was clinical professor at the University of Miami. I had two more children after that. ... A house with a big mortgage," he says. "I could lose all of that. But that was so real and so detailed. You know how you get the feeling in your gut, in your bones? There was no trick to this."
Before Oprah and Dr. Oz entered the studio, Dr. Weiss led the audience through a 45-minute past-life regression exercise.
Listen as Dr. Weiss explains how past-life regression works. 
Between one-quarter and one-half of the audience say they had some success being hypnotized and recalled old memories from their current lives. Some even say they experienced visions of past lives.
One woman says she recalled how, in a previous life, she was a man who was murdered by someone while in a swamp. "I could feel blood running out and I could see my attacker and I was killed with a knife," she says. "It was okay because later I saw my dad who has passed and my sister who's passed."
Another woman, who is African-American, says she had a strange experience in past-life regression. "I was white, and I was a nun," she says. "I'm, like, I'm
so not a nun, so that was weird."
A third woman, who says she does not have children, says past-life regression revealed to her several past lives in which she did have children. "I think I so desperately want children that every single time you took me back, I had children," she says. "And they lived, and I died."
Dr. Weiss says these experiences are all quite common. "We change race, we change religions because we have to learn from all sides. Souls don't have those characteristics. We're all connected. It's not about color or race. Sometimes we have to be nuns because we learn to live spiritual lifetimes," he says. "We've all been black, we've all been white, we've all been brown, we've all been red. We've been everything because we have to learn from all sides. ... You have to learn from all sides, and that's part of our learning here on this planet."
Dr. Weiss says hypnosis helps people access their past lives by focusing patients' concentration while their bodies are relaxed. "It stops the clutter, the everyday mind, from getting in the way," he says. "You go right to the subconscious. You can go right to where the memories are. You're still here, you're safe, and you don't go anywhere."
Dr. Oz says there is a medical explanation for this phenomenon. In the same way that a driver on the highway "on autopilot" can miss her exit, another person forgets her oldest memories. "What's happening is this part of your brain, the cortex—the part that's doing all the executive function—it's continually repressing your reptilian brain—the deep part of the brain that has our most ancient memories in it," he says. "But if you can free that part of the brain, you can express yourself and find out minute details of your childhood or maybe things beyond that."
That part of the brain that houses ancient memories has a strong pull on our lives, Dr. Oz says. "We have spent so much time on these shows trying to get folks to change behaviors, whether it's cigarette smoking or weight loss or addictions or whatever it may be," he says. "You begin to realize that 90 percent of what drives us is not what we're thinking about; it's not the cortex—the part ... that's making logical decisions. It's the emotional, decision-making quality, and that's the reptilian brain."
While there is no scientific proof that past-life regression like the kind Dr. Weiss practices can actually access previous lives, Dr. Oz says keeping an open mind is important. "I feel very strongly about that because this has so much wonderful healing potential," he says.
Dr. Oz says crucial advances in the history of medicine would have been impossible without someone having an open mind. One such advance, he says, is in understanding bacteria. Dr. Oz explains that Ignaz Semmelweis, a physician in 1840s Vienna, observed higher rates of a deadly fever among infants delivered in a hospital than those delivered by home birth. His hypothesis about the cause of this fever made him the target of vicious attacks by the medical establishment and cost him his job. He was eventually committed to a mental asylum, where he died.
"Semmelweis said it must have something to do with our hand washing techniques," Dr. Oz says. "Look at your hands—do you see anything on them? Nothing on them, right? The crazy idea that there might be bacteria on your hands causing infections was completely out in left field back then. The germ theory was still 40 years away. ... Too often in medicine, we are entrenched in the belief that we have to understand 'why' before we take that big leap forward to look into the reasons for it. That's what fascinates me so much about this whole [past-life regression] process."
One former Oprah Show guest seems like a perfect candidate for past-life regression therapy with Dr. Weiss. As a funeral home director, Leon—who had difficulty quitting smoking—is literally around death all the time. "We thought that he might have an interesting experience," Oprah says.
Leon says he has had a somewhat rocky relationship with his sister and dreams of flying almost every night.
"As I count backward now from five to one, go back into your childhood and let yourself remember a memory from when you were young," Dr. Weiss says to begin the hypnotism.
Leon says he remembers being 6 years old. "I remember my mother being gone one night, and they were telling me that she was going to bring a baby home," he says. He also remembers being sad because his older sister is teasing him.
"You don't need to feel sad because you can fix it," Dr. Weiss says. "You know the real core of it."
Dr. Weiss next brings Leon even further back...into a past life. "Be there," Dr. Weiss says. "What's happening to you?"
"I'm just floating. I'm on a plane. It's an old plane," Leon says.
Leon first says his plane is having trouble staying level. Then he says he sees smoke and other planes nearby. Dr. Weiss says he thinks Leon is describing a past life in which he is fighting on a war plane.
Leon says he's confused about who to shoot, and his plane gets hit. "It's my fault," he says. Dr. Weiss says, "Because Leon refuses to shoot his guns, his own plane crashes. I see his reluctance to kill others in this past life as the mark of an advanced soul. ... Leon has a fear of heights. He has a fear of drowning. This is where it comes from—from that past life."
Before starting the regression, Leon says he would like to learn how to improve his relationship with his sister—and find out why he can't stand feeling any physical pressure on his chest. His next regression answers both of those questions—and sent chills up everyone's spines, including the cameramen.
Leon begins by telling Dr. Weiss he feels like he's kneeling and his body is swelling. "It was crushed," he says. "My whole body. ... It's a garbage compactor or something. A car crusher."
With Dr. Weiss's guidance, Leon recalls getting hit in the head while watching helplessly as a woman is being raped. Leon says he never saw the rapist because he was too far away. "I wasn't very brave," a crying Leon says.
Dr. Weiss tells Leon he couldn't have done anything to save her. "You couldn't have done anything. Even if you had tried to stop it, you probably would have been killed first, right?" Dr. Weiss says. "Let go of any guilt from that time."
Dr. Weiss asks if Leon knew the woman being raped. "It was my sister," Leon says.
Leon says he instinctually knew the stranger who was getting raped in a past life as his sister in this life. "I didn't see her face," he says. "It was an energy. It was just her. There was no doubt about it."
Dr. Weiss says Leon's current feelings toward his sister are rooted in the guilt he's carried over from a past life. In the short time following his regressions, Leon says his relationship with Lynn has already improved. "I don't have any anger toward her. I'm totally accepting of her and our differences," he says. "I feel completely at peace and just love."
Lynn says she never felt her relationship with Leon was rocky, but she says they have worked hard at maintaining it. Watching the tape was a mind-blowing experience, she says. "I couldn't believe what I was watching, and he was obviously so deeply affected," she says. "I didn't have any particular feelings about it like I was reliving it because it was completely his experience."
Leon says part of him doesn't want to believe in the regression. "But I keep going back to it, and there's no other explanation. I'm trying to disprove it in my mind, but there are other things that just lead me back to it."
One of those things is a message Leon says he received during his regression session. "They want me to tell people they're okay," he said while hypnotized. "The dead people."
Leon says he's always been comfortable around the dead and now he knows why. "I just get the feeling that they're at peace no matter the circumstances of their deaths," Leon says. "I feel from them that they're at peace and that they want me to guide their families through this process and heal their families. It's just a feeling."
As part of his research for the show, Dr. Oz agreed to be past-life regressed. He admits the experience was intimidating for him. "I love when there's data. If there's information out there, I get my arms [around] it, and I'm really comfortable," he says. "When we go down this pike, I get really uncomfortable."
During his 60-minute session, Dr. Oz says he recalled a dream he had before he started kindergarten.
"In this dream, my father is taking me out by the hand to individual older men who are wearing these velvety gowns and they're wearing [fez hats]," he says. "They have these old parchments and scrolls and they're writing down things like my lessons, and he's taking me from place to place, and they're not joking around. They're very serious about what they're doing, and it just sort of seems to me that they're planning my life."
Dr. Oz says he then remembered starting school and being disappointed. "Then I ended up from there in this sort of ether. This space that many of my patients actually have described to me," he says. "I felt like there was a stream of people going past me, but they were energy. They didn't have faces. They were trying to teach me, but I wasn't ready to hear it yet."
Dr. Weiss says the most common question he's asked about past-life regression is if there is a presence of God in the process. "I find God everywhere in this," he says.
Think of the experience as an ice cube, Dr. Weiss says. Ice cubes are solid until they're melted by heat energy. They become water, but if you add more heat energy, that water will turn into steam. The same molecule—H2O—is still there, just in a different form.
Dr. Weiss says people are like ice cubes. "We're the solid part, the condensed part. We think we're separate from everybody else. We're not. If you heat us with love energy—not heat energy but love energy—we melt into a spiritual sea," he says. "And if you keep heating with love, you find God. God is the steam. God is beyond the steam—the organizing wisdom that's in every atom of our being."
In the end, we're not so separate, Dr. Weiss says. "We're not different from each other," he says. "We're all souls, and souls are all connected."
Now that Dr. Oz has had a past-life regression experience, he understands there will be skeptics. "You know, Oprah, there will be a lot of folks who very understandably say these are the wishful desires of desperate people," he says.
So does Dr. Oz believe in past-life regression? "I've got to say I don't know if it's past lives. We can get into a long debate whether these are spiritual beings touching us," he says. "A hundred years ago in this country, we were more comfortable with these discussions than we are today. I think part of that is we have gotten addicted to the same serum that I'm taking, which is the belief that the answers are always going to be there in front of us. And sometimes we've got to take that leap, just to believe to test it out. We don't have to advocate it, but we do have to evaluate it."
Dr. Oz says he does feel like there is a collective unconsciousness out there. "I actually in my heart think that all of our minds are connected and all of these minds in history are then reflected, and we're feeding into this energy system that we can tap into. It's like karma. You can bounce into it. It bounces you back," he says. "So what I really think we want to do is challenge people to the belief and understanding that life is not as real as it seems. There's other stuff out there."
