David's post on efforts to make Brandeis University more "diverse" by making it less distinctively Jewish gives me a good opportunity to write about a pet peeve: The conflict between diversity within institutions and diversity across them.

Those who argue for diversity in higher education implicitly envision a school that has a "critical mass" of whites, blacks, Jews, Hispanics, and other groups. Such a university may well be internally diverse (at least in an ethnic sense), but if every school pursues this ideal, than they will all look more or less alike on the ethnic dimension, or whatever other criterion is chosen as the focus of diversity promotion. There will be diversity within institutions, but very little diversity across institutions.

By contrast, if Brandeis continues to be a distinctively Jewish school, Brigham Young continues to be a distinctively Mormon school, and so on, these schools can make unique contributions to American higher education that might otherwise be lost. Although Brandeis and BYU may not be internally diverse, they definitely add to the overall diversity of the American higher education system in two important ways. First, they give students who want to attend a distinctively Jewish or Mormon school an option they would not have if all schools stick to the internal diversity model. Second, faculty at a distinctively Jewish or Mormon school might well pursue research on subjects that are ignored or at least deemphasized at other types of institutions. Brandeis' traditional focus on hiring faculty who study the history of Judaism and the Jewish people is an example of the latter.

To be sure, a school built around a particular group identity will have weaknesses as well as strengths. But the weaknesses are offset by the fact that there will always be hundreds of other schools that do not try to foster a distinctive group identity. Students and faculty who don't want to be associated with a distinctively Jewish school have plenty of options, even if they can't attend Brandeis. The question is not whether there should be a large number of internally diverse schools, but whether all schools should be that way. Both students and scholars will be worse off if we exalt diversity within institutions to such an extent that diversity across institutions is eliminated.