 According to the weaker interpretation of impartiality described above, moral rules reflect this division of labor. (By the “weaker interpretation” is meant the thesis that moral thinking avoids being self-centered because it upholds a single set of rules or norms that apply equally to all human beings.) Consider, for example, the duty we normally have to help others, even when they are strangers. If someone is in need, and asks for your assistance, that gives you a reason to help him, and you should do so, provided that compliance with such appeals is not overly burdensome. Notice the escape clause: it builds into the duty to aid others a recognition of the importance of each person having a significant degree of control over his own life. Common sense morality assumes that what we owe to others might call for some sacrifice of our own good, but also that in the ordinary business of life the degree of sacrifice should fall within certain limits, so that we can make good use of the responsibility we have been given as adults to seek our own good. The balance struck by moral rules between the claims of self-interest and the claims of others is what makes it possible for those rules to be recognized and accepted as appropriate. These rules leave us free to volunteer to make greater sacrifices; but such greater sacrifices are not required of us except in extraordinary circumstances (wars, disasters, emergencies).