I was struck by a bicyclist riding at high speed on the sidewalk. I wound up on my back, and the cyclist, also downed, was writhing in pain. Amazingly, I was unhurt, but because of my shock and anger, I got up indignantly and walked away. Later, I questioned my behavior. What if the cyclist had really been hurt? Did his wrongful action warrant mine? —Name Withheld, Los Angeles

WHEN A QUESTION includes the phrase “writhing in pain,” it may well imply an ethical duty or at least a call for ordinary compassion. Even if the cyclist acted thoughtlessly or broke the law, that doesn’t place him beyond moral consideration. First respond to his writhing in pain, then sort out who’s to blame. In your defense, though, the shock from being knocked to the ground might have prevented you from thinking clearly, so don’t reproach yourself too sternly. It’s legal in many cities to ride a bicycle on the sidewalk. I’m not suggesting that we casually disregard the laws we actually have, but that people who violate them are still worthy of humane treatment.

—Adapted from “The Ethicist” in The New York Times Magazine