(CNN)While captive for more than seven years at the infamous Hỏa Lò Prison, nicknamed the "Hanoi Hilton," in Vietnam, US Navy Admiral James Stockdale was tortured more than 20 times.
Enduring some of the harshest conditions a human can face, Stockdale led fellow service members held as prisoners of war with a thought process that combined open-eyed realism with a hope that circumstances would eventually improve.
Holding realism and idealism together is key to surviving any severe situation, whether that be imprisonment, depression or a pandemic, said author and management consultant Jim Collins, who told Stockdale's story in the popular 2001 business book "Good to Great."
In the book, Collins recounted a walk with Stockdale on the Stanford University campus decades after the officer's return from Vietnam. Stockdale had embarked on an academic career focused on the Stoic philosophers of ancient Greece.
Who was least likely to survive prison and torture?
"Oh, that's easy," Stockdale said. "The optimists." They were the prisoners who naively told themselves they would be out by Christmas, which would come and go. Then they would pin their hopes to Easter, only to be thwarted again.
"They died of a broken heart," Stockdale told Collins.
As many people face holidays shadowed by the pandemic -- many having lost loved ones and separated from friends and family, Stockdale's insights are valuable in navigating the next few months.
"The brutal facts are the brutal facts," Collins told CNN. "We won't be out of this either by Christmas."
The Stockdale Paradox
Collins crystallized this concept as the Stockdale Paradox, asserting that resilience in grim circumstances requires retaining "faith that you will prevail in the end, regardless of the difficulties." At the same time, you must confront "the most brutal facts of your current reality, whatever they may be."
For many, that means acknowledging how widespread and deadly the pandemic is while also believing that vaccines will eventually be widely available and we will get through it.
One of the best ways to seek perspectives, Collins explained, is by grounding yourself in reading about past crises, and contextualizing this moment as just part of the arc of a longer lifetime.
"This is a great time to read biographies and to read histories. Others have endured longer and harder. And it shows that we can endure longer and harder," he said.
These narratives could include how US President Abraham Lincoln grappled with depression before leading the nation through the Civil War and US President Franklin Delano Roosevelt contending with his own polio before navigating the Great Depression and World War II. Author Doris Kearns Goodwin covers the presidents and their crises in the 2018 book "Leadership: In Turbulent Times."