While on a tour of California's giant sequoias, the guide pointed out that the sequoia tree has roots just barely below the surface. "That's impossible!" a man exclaimed. "I'm a country boy, and I know that if the roots don't grow deep into the earth, strong winds will blow the trees over."

"Not sequoia trees," said the guide. "They grow only in groves and their roots intertwine under the surface of the earth. So, when the strong winds come, they hold each other up."

There's a lesson here. In a sense, people…