 Most discussions of sortals focus on kinds of physical objects, but by the definitions given many sortals also apply to abstract objects. And in some of these cases the question what is a criterion of identity becomes even more difficult. We can ask how many new ideas a political candidate has, how many governments Italy has had since 1950 and how many books David Wiggins has written. Ideas, governments and books (in the sense of type of book, not specific copies) are all abstract objects. We comment on changes in corporations over time—Apple has grown—which implies identifying Apple over time in spite of changes. But we are far short of having criteria to make decisions in harder cases: Did Rice Institute cease to exist in 1960 or was it just transformed with a new name and some changes in charter to Rice University. The buildings, faculty and students all persisted, but did the educational institution?