I'm going to challenge whether theirs is the best way it can possibly be done.

If we're going to challenge human nature, the critics ask, why not start with the latter rather than the former?

"He's going to challenge the other guys to be their best."

The union went to court to challenge the arrogant act.

In 1989 the club went back to court to challenge that decision.

"And I am going to challenge him on your behalf."

Wan looked around to see if anyone was going to challenge what he said.

"I like the fact that someone is going to challenge him," she said.

"I knew he was going to challenge me," Thomas said.

And if anyone's going to challenge their behavior, it has to come from one of them.