Much of my work has been concerned with what we could call the politics of the boundary. The meaning of "politics' here is very broad, having to do with all sorts of influence and power, but especially the power to define and privilege, include and exclude, render central or peripheral. Though this may involve matters "outside" science (a fraught frontier if ever there was one) it need not. Some of my reasons for working on the nature-nurture problem stem from concerns about publicly contested issues of, say, intelligence, race or sex, but most have to do with the kinds of distinctions that are made in the scientific work that draws on and feeds these larger disputes. Any theory carves the world in particular ways and so legitimates some entities and distinctions while leaving others beyond the pale--secondary, invisible or unintelligible.