 Finally, what of Butterfield’s criterion of broader social impacts? Kuhn retained this criterion in The Copernican Revolution, but revolutions increasingly become changes in specialist communities in his later work, since those communities insulate themselves from the larger society. In the chapter on the invisibility of revolutions in Structure, Kuhn tells us that a tiny subspecialty can undergo a revolution that looks like a cumulative change even to neighboring fields of the same scientific discipline. In this respect Kuhn remained an internalist.