To assist them, she conjured a metaphor: “If you were told by your precious one’s physician that they had a life-threatening condition and that the only known protocol or the best protocol for that condition was an experimental surgery, you’re very likely going to ask for a second opinion.” Anyone would ask questions, do research, she explained — but at some point you have to decide: “If you go forward, it’s not because you have moved beyond all doubt. There are no guarantees. If you go forward, it is because you have moved beyond all reasonable doubt.”