PHOENIX — When former Vice President Joseph R. Biden Jr. traveled to Senator John McCain’s Arizona ranch last Sunday to spend a few hours with his ailing friend, the two reminisced about the “crazy senators” they had served with, the overseas trips they took together for decades and the friendship Mr. McCain forged with Mr. Biden’s two sons.

But the conversation on the sun-splashed deck off Mr. McCain’s bedroom was not all nostalgia.

“Here John knows he’s in a very, very, very precarious situation, and yet he’s still concerned about the state of the country,” Mr. Biden said in an interview. “We talked about how our international reputation is being damaged and we talked about the need for people to stand up and speak out.”

As he battles brain cancer and the debilitating side effects of his aggressive treatment, Mr. McCain himself is reckoning with his history and the future, as he and a stream of friends share memories and say what needs to be said.

No one is saying goodbye, not explicitly. The son and grandson of admirals, Mr. McCain “doesn’t like overt sentimentality,” as his friend the former chief of staff Grant Woods put it. But his visitors are telling him they love him, how much he has meant to them — and together they are taking care of unfinished business.