A group of doctors were out duck hunting, when a large bird flew overhead.
The family doctor raised his gun to shoot, but then lowered his gun saying, “I am not sure that is a duck.”
The psychiatrist raised his gun, but then lowered it again saying, “I know it’s a duck, but I’m not sure that it knows it’s a duck.”
The surgeon raised his gun and blasted the bird out of the sky. He turned to the pathologist and said, “Go see if that was a duck.”