In another sense, everything is the ruin of what came before. A table is the ruin of a tree, as is the paper you hold in your hands; a carved figure is the ruin of the block from which it emerged, a block whose removal scarred the mountainside from which it was hacked; and anything made of metal requires earth upheaval and ore extraction on a scale of extraordinary disproportion to the resultant product. To imagine the metamorphoses that are life on earth at is grandest scale is to imagine both creation and destruction, and to imagine them together is to see their kinship in the common ground of change, abrupt and gradual, beautiful and disastrous, to see the generative richness of ruins and the ruinous nature of all change. “The child is the father to the man,” declared Wordsworth, but the man is also the ruin of the child, as much as the butterfly is the ruin of the caterpillar. Corpses feed flowers; flowers eat corpses. San Francisco has been ruined again and again, only most spectacularly in 1906, and those ruins too have been erased and forgotten and repeated and erased again.