In Torah portion Ki Teitzei, we are commanded to shoo away a mother bird before we take her young or eggs, and promised that if we do so, we will be rewarded with long life (Deut. 22:6-7). Two great Jewish sages, the Rambam (1138-1204) and the Ramban (1194-1270), disagree about the reason for this. The Rambam says we send away the mother bird to avoid causing her the pain of seeing her offspring taken away. The Ramban says it’s actually for our own sake that we shoo away the mother bird, because it elevates our character to show concern for the feelings of another.
According to the Maharal (16th cent.), this disagreement boils down to a fundamental question: Is the world for me, or am I for the world? The Rambam holds that “I am for the world,” i.e. I exist to improve the world around me. The Ramban holds that “the world is for me,” i.e. the world exists for me to improve myself. That’s why the Rambam focuses on the bird’s pain, while the Ramban focuses on the effect on our own character.
Which understanding is correct? Both, of course. We are here to improve the world, but we can’t do that without improving ourselves.