When we are young, we imagine that we are doing everything ourselves. We have our work because we deserve it. We believe that we generate our own opportunities, our own luck, our own unstoppable bodies. There must be something to this, we intuit, that our fate varies according to those powers of attention which we bring to the frontiers of our young lives. But as we grow older, we grow wiser as to the extent of those powers; there is another, profounder way, in which we are dependent not only in visible ways on the inheritance of others but literally and physically on what we have been given by those who have gone before us.