Admiral James Stockdale spent seven years as a POW in North Vietnam.

He was tortured physically and psychologically (the details are horrifying), but he survived, returning to active military duty upon his release in 1976. He spent the rest of his working years in public service, his career culminating in a run for vice-president in 1992 on Ross Perot’s ticket.

Author Jim Collins interviewed Stockdale for the now-classic 2001 business book Good to Great: Why Some Companies Make the Leap and Others Don’t, and the former POW laid out the philosophy that carried him through a seven-year waking nightmare.

I never doubted not only that I would get out, but also that I would prevail in the end and turn the experience into the defining event of my life, which, in retrospect, I would not trade.

This seems impossible—who could maintain that kind of faith in a POW camp?—but Stockdale explained:

You must never confuse faith that you will prevail in the end—which you can never afford to lose—with the discipline to confront the most brutal facts of your current reality, whatever they might be.

Collins termed this “the Stockdale Paradox,” and it’s a useful construct. We often refuse to confront the stark reality of our situation, but until we see things as they are, we can’t begin to change them. Yet seeing the cold hard facts doesn’t have to shake our faith in the ultimate outcome: that we will “prevail in the end.”

It’s a question worth asking regularly: “Where can I be more honest with myself while maintaining faith in my eventual success?”