It’s been a real bad day. One of many lately. But then the radio decided to have a chat with me. It said, “Hey, Soul Sister!”

I love it when the radio wants to chat. This time it reminded me that music can always make me smile, even on bad days. It reminded me that I love R&B—even though “Hey, Soul Sister,” by the group Train, isn’t an R&B song.

And it reminded me that you need to have soul to get through tough times.

By soul, I’m not talking about the spiritual self. I’m talking about a deep well-spring of feeling, spirit, emotion. Power. I’m talking about that part of us that makes us keep going when we don’t think we can. Here’s how some others have described it:

“The powers of the soul are commensurate with its needs.”

—Ralph Waldo Emerson, essayist

“Man is so made that when anything fires his soul, impossibilities vanish.”

—Jean De La Fontaine, poet

“Of the three prerequisites of genius, the first is soul, the second is soul, and the third is soul.”

—Edwin P. Whipple, essayist

“Every hardship, every joy, every temptation is a challenge of the spirit, that the human soul may prove itself.

—Elias A. Ford

“The soul would have no rainbow had the eyes no tears.”

—John Vance Cheney

“Valor is common but great souls are rare.”

—Bernard Joseph Saurin, dramatist

“Great souls have wills; feeble ones have only wishes.”

—Chinese proverb

“Out of the night that covers me,

Black as the Pit from pole to pole,

I thank whatever gods may be

For my unconquerable soul.

In the fell clutch of circumstance

I have not winced nor cried aloud.

Under the bludgeonings of chance

My head is bloody, but unbowed.…

It matters not how strait the gait,

How charged with punishments the scroll,

I am the master of my fate:

I am the captain of my soul.”

—W. E. Henley, poet, in Echoes, 4