Let's call one doctor Ted and the other doctor Bob. We will also replace the verb "to doctor" with "to treat". We will say that Bob is sick and Ted is doing the treatment. So, "the doctor doing the doctoring" is Ted. Now it will be easy to understand: When Ted treats Bob, does Ted do the treatment in the the way that Bob would as a doctor, or does Ted do the treatment the way he (Ted) usually treats someone? That is, will Ted say, "Bob, you are a doctor. How would you like me to treat you for this?" Or will Ted just think, "I am a doctor, too. I will treat Bob how I feel is best"?

假定二人都是医生。动词doctor是看病，治(疗)病。 先从字面上直译分析为： 一个医生给另一医生看病时，看病的医生是按被治病的医生想让人治好病那样看病，还是看病的医生按他自己想要治病那样看病。 意译是： 一个医生给另一医生看病，他应当按生病医生的治法看病，还是按他自己的治法看病。