So even when we have the writing, and this is, once again, some images of early writing. This is the famous Sumerian cuneiform, this is a Sumerian cuneiform tablet here. Even when we have it, and obviously we have much, much more writing as we get to the more recent past, we have to be very, very, very skeptical. We know today, even if two observers observed something yesterday, something that just happened, they might have very, very different perceptions of what happened. So even if there's writing, we have to be skeptical. But things get, in some ways, even more interesting before we have writing, when we go into prehistory. You might wonder, how do we know anything about what happened if there's no written accounts?