My kids love ethics! I think it's partly because it makes them feel older to discuss such "heavy" concepts. I try to guide them in discussions almost daily that pertain to this topic. It's easy to relate to characters in a story. We read a cute, little story called The Fox and The Falling Leaves about a fox who is just incredibly disturbed that his favorite tree is losing all its leaves. He tries to save them, but to no avail. There is one adorable illustration with the leaf tucked into the bed next to him as he slept. The ending is kind of abrupt and not at all what I expected, but the children enjoyed it.
After reading the story I asked the kids to write about whether or not it is "right" or "wrong" that the leaves fall off the trees. I got several really insightful answers: Right- because it lets new leaves grow, it makes things more beautiful. Wrong-because it gives us more leaves to rake or makes the trees look uglier-were just a few responses.