He remained competitive, vain and occasionally unbearable.
But he became an excellent physician.
Years after their first conflict, Cross presented a case at Daniel's national meeting and paused before giving his conclusion.
"I used to think expertise meant arriving at certainty faster than everyone else," he said. "I now think it means knowing which uncertainty you still owe the patient."
Daniel recognised the sentence as something close to his own teaching.
He did not claim it.
After the talk, Cross said, "You're not going to mention that I stole your line?"
"You improved it."
Cross sighed. "I preferred you when I disliked you."