My neighbor died a couple of weeks ago, just days after she told me she’d decided to undergo more chemotherapy. A long stretch of on-again, off-again radiation and chemo had failed to eradicate her cancer, and her life had become, in her words “pure torture.” Still, she wasn’t ready to let it go.

On that same grim Tuesday, a friend who’d undergone months and months of miserable treatment for both heart and lung disease that left him almost completely incapacitated, announced that he was quitting all life-saving efforts, leaving the hospital and going home.

One patient, hopeful to the end. Another whose hope had seemingly run out. Which of these individuals would you consider the most irrational?

Recently, I’ve read a number of studies and personal stories about the role hope plays in health care. Most agree that optimism creates, as one put it, “positive energy that can nourish both body and soul.” But some also argue that the old gung ho spirit we Americans are so proud of in ourselves can blind certain patients and their health care providers to a reality that would be more usefully viewed minus the rose-colored glasses.

In an essay in The New York Times called “The Cancer of Optimism,” Haider Javed Warraich, M.D., writes about one case in which the “sense of righteous optimism” about the power of medicine that he acquired in medical school convinced him to recommend a very risky procedure for a desperately ill patient. The patient died, and since then, “I have come to believe that I was a victim of irrational optimism, a condition running rampant in both doctors and patients, particularly in end-of-life care.”

Warraich, a resident in internal medicine at Beth Israel Deaconess Medical Center, cites studies we’ve written about here before, which found that patients by and large want to know the truth no matter what it may be so that they can meet the end of their lives on their own terms, making their own decisions about medical, spiritual and personal matters.

However, the studies showed, doctors too often hold back difficult facts in the wrongheaded belief that they’re protecting the patient or robbing the patient of all hope. That can have dire consequences, Warraich notes, spurring physicians to prescribe treatments that probably “won’t save patients’ lives, but may cause them unnecessary suffering and inch their families toward bankruptcy.”

On the other hand, hope can empower patients and their families to become more aggressive in understanding their disease and all the possible treatments, including the latest breakthroughs. Deborah J. Cornwall, the author of Things I Wish I’d Known: Cancer Caregivers Speak Out, says that “sustaining hope in the face of cancer is both critical and problematic.” But it is not about denying the inevitable.

“Decisions about when a patient will die, and where, are part of creating hope for loved ones,” she writes in her book, which is based on interviews with 86 cancer caregivers and numerous patients and survivors.

By quitting extreme measures, my friend insists he has not given up hope. “I’m hopeful that I’ll die at home, with my sister and brother nearby and with as little pain as possible,” he says. “I hope to go peacefully, with whatever dignity I have left.”

My neighbor’s son told me that during the last several months, his mother’s suffering was a terrible thing to watch and that he’d silently wished she would let nature run its course. “But,” he says, “she hoped she would see my 2-year-old, her granddaughter, grow up. Hoping for that made her happy, even when she knew in her heart it probably wouldn’t happen. That made the suffering bearable.”