只要一个人能保持那种心态，他就依然年轻。

原文英文

"I dread to come to the end of the year," a friend recently said to me, "it makes me realize I am growing old."

William James, the great psychologist, said that most men are "old fogies at twenty-five." He was right. Most men at twenty-five are satisfied with their jobs. They have accumulated a small stock of prejudices that they call their "Principles," and have closed their minds to all new ideas; they have ceased to grow.

The minute a man ceases to grow—no matter what his years—that minute he begins to be old. On the other hand, the truly great man never grows old.

Goethe passed away at eighty-three, having finished his Faust only a few years earlier; Gladstone took up a new language when he was seventy. Laplace, the astronomer, was still at work when death caught up with him at seventy-eight. He died crying, "What we know is nothing; what we do not know is immense."

And there you have the real answer to the question, "When is a man old?"

At seventy-eight, Laplace died young. He was still unsatisfied, still sure that he had a lot to learn.

As long as a man can maintain that attitude of mind, as long as he can look back on every year and say, "I grew," he is still young.

The minute he ceases to grow, the minute he says to himself, "I know all that I need to know," that day youth ends. Whether he is twenty-five or seventy-five, it makes no difference. On that day, he begins to be old.