Public monuments are more than history. They are a society making a statement about the things and people and values that are important to that society. If what is important to a society changes, I think it's reasonable to change what that society is publicly honoring. History is not destroyed by being consigned to museums and textbooks. Those museums and textbooks must be inviolable, but the nature of public space requires that it be constantly shaped by those who use it, since it has a corresponding role in shaping us.

A statement from a friend on this has stuck in my memory for years now. We should tend the fire, not worship the ashes.