In March of 2006, Emily O’Conner was sure that she was on the cusp of enlightenment. We had spent the last seven days on a silent meditation retreat together in the holy city in India for Buddhists called Bodh Gaya. I was the director of her abroad program, and Emily was my student. Late in the night she filled her journal with a scrawl about what she had learned in the silence. She wrote that contemplating her own death was the key to deeper spiritual realizations. A few paragraphs later she wrote the words, “I’m scared that I will have this realization and go crazy.” Then, on the last page, in a paragraph all by itself, she penned her last words — a final resolution to her spiritual progress: “I am a Bodhisattva.”

When she was done writing she wrapped a shawl around her face, stood on the ledge of the three-story building, and jumped. One of the other students on the program found her body an hour later.

In Tibetan Buddhism a Bodhisattva is a fully realized being whose deep spiritual insights have opened the door to Nirvana. However, rather than stepping though the threshold, Bodhisattvas pledge to remain on earth to help other people to the same realizations. In a way, you could think of a Bodhisattva as a sort of god that exists beyond the realm of life and death. Almost three millennia earlier, in a spot less than a mile from where Emily took her own life, the man who would become known as the Buddha had a similar realization. He spent the remaining time he had on earth translating his knowledge to a growing community of followers.

I have often struggled with the apparent contradiction of how these spiritual lessons can be so profoundly beneficial for millions of people while at the same time be so profoundly damaging for a few. Indeed, even in the time of the Buddha, some of his followers pursuit of spiritual perfection ended in suicide. In the vinaya, early Buddhist writings recorded in Pali, there is a story of when Buddha asked his monks to meditate on the inevitable decay of their own bodies. He instructed them to sit in graveyards and watch bodies decay (a version of this practice called chod still exists in modern Tibetan Buddhism). Once he gave the lesson, the Buddha headed off into the mountains to mediate, trusting his flock to understand his commands. But the monks who followed the lesson were so overcome with insight that they committed suicide. Others implored a recluse monk named Migalandika to slit their throats. When he returned, the Buddha put a stop to the carnage. The scholar Timothy Brook recently wrote that Migalandika’s story became canonized because it took aim “at the hopeless literalism that tends to arise when religious followers devise institutions they hope will enable them to live up to the ideals of an absent founder.”

This sort of literal interpretation in the face of metaphysical truths inflects the rhetoric of fundamentalists from ISIS to rogue American evangelicals. There’s no question in many of our minds that the world is more complex than the one defined by pure rationality. Science has its limitations, and any rational attempt at answering a moral question usually ends in a gray area, not in stark black or white. But people who can presume a direct connection to divine knowledge — either through textual fidelity or direct personal experience — don’t have ambiguities anymore.

The violent plague of Islamic fundamentalism in the Iraq and Syria has left hundreds of thousands of people dead in the name of an ultimate truth that is hidden from ordinary eyes. ISIS fighters carry out objectively heinous acts without a qualm to the moral order of the world they inhabit because their eyes are fixed on heaven.

In this way, the person who seeks enlightenment without regard to their own place in society risks falling into a similar disconnect that a jihadi does. A few turn violent, like the so-called “Bin Laden of Buddhism,” who encourages genocide against muslims in Burma. More frequently, the inward focus of eastern religions makes the struggle for ultimate knowledge personal, but even that turn can undermine the social order. Today the star yoga guru Bikram Choudhury appears to have rationalized his inappropriate sexual advances on his students through his spiritual insights. He now faces multiple sexual assault allegations. The same fate befell John Friend founder of Anusara Yoga a year ago and dozens of spiritual leaders from Osho to Sogyal Rinpoche and Michael Roach before that. All claimed to be closer to a universal truth their their students. And they all took advantage of their power.

Of course, the danger doesn’t only lie in the teacher. Anyone searching for ultimate knowledge runs the risk of discovering their own fundamental laws of the universe. After she died, I began to research similar cases to Emily’s. I wanted to try to understand how someone could become overcome with potentially dangerous spiritual insights after a meditation retreat. To my surprise, examples proliferated. In a matter of weeks I collected six journals of people who took their own life or ended up in mental asylums. I spoke to directors of alternative universities who told me that every year they send students to mental health professionals after bad experiences on their meditation cushions. Moreover, I met Tibetan scholars who told me about a curious condition among inveterate meditators called “lung” that can drive people to the brink of insanity. The diagnosis of lung goes back centuries — long before meditation ever came to America. I interviewed a neuroscientist at Brown University who has collected hundreds of anecdotes from mediators whose progress was cut short when they began to lose touch with reality.

Raising the notion that meditation can occasionally be dangerous is not popular among practitioners. Most people correctly note that mindfulness has improved their quality of life. They point to studies that show all sorts of qualitative and quantitative improvements to cardiovascular function, memory, and even empathy. But, like all things in life, nothing is truly black and white. Meditation and spiritual inquiry can be beneficial, maybe even necessary, but that doesn’t mean there aren’t risks.

I can never know why Emily killed herself, but it strikes me as the sort of tragedy that people who are trying to live spiritual lives try to shy away from. It is undoubtedly worthwhile to search for spiritual insights.

We can uncover deep and hidden parts of our own psyches in the process and perhaps become better people. The problem begins when the search ends. Just like the monks in Migalandika’s time, Emily believed that she had reached a sort communion with a divine truth. Enlightenment was a destination that she could observe just like a natural law. And her insight meant that she was infallible. Her journey was complete. At that point, what would it matter if she took her own life?

Enlightenment, if it exists, may be a goal worth striving for, but it is not worth achieving. While we may never understand the ultimate clockwork that makes the universe work — whether it is the law of karma or grace from a benevolent God — one thing that we do know is that people who claim to understand ultimate knowledge most often don’t feel that they need to follow the same rules as everyone else.