Standing in the middle of my living room is a tree. This ought to seem strange and uncanny, a violation of categories. Trees are part of nature, and nature belongs in the category “outside.” This tree has crossed the threshold between inner and outer, human and natural, and by rights should be as disturbing as the Birnham Wood that walked and stood before the gates of Dunsinane. To be honest, it isn’t a real tree. But it looks like one, and in many other living rooms at this time of year the tree is quite real, pine smell, shed needles, and all.