Photographs, murals and statues inescapably point to the past, but the past is infinite - we could display anything, from primordial soup to yesterday's breakfast. So we have to choose. That's why the art we display in our public places reflects what we think today about the past. It tells us what we want to celebrate, cherish and remember. That is why our choices about murals and statues are important. That's why we put up monuments to heroes, not criminals. So when people say we should take down art depicting oppression, slavery or genocide, we are not saying we want to erase history, we are saying that perhaps today we should stop celebrating oppression, slavery or genocide as though they were good things. And it's hard not to think of people who defend these displays as people who still think they were good things.