First, let's look at what Todd says. First, he provides three purposes or goals for higher education:
(1) to develop human capital, (2) to educate and develop critical thinking skills and intellectual self-discovery and character in students, and (3) to develop individuals who can participate as responsible citizens in a free and democratic society.Since I more or less agree with these, I won't address them specifically. However, Todd uses these goals as a launching point for his arguments for diversity. The first goal "develop human capital" doesn't require diversity, he says, but the second does. He writes:
Ideological diversity has a lot to do with this [critical thinking skills and intellectual self-discovery]. The purpose of education should be to teach students how to think, not what to think. I don't know how you can teach students to analyze arguments and determine the truth value about claims about the world if you don't expose them to a variety of ideas. As Greg Ransom observes the presence of an intellectual orthodoxy on campus can severely hamper student's critical reasoning skills. Ransom's experience is that many students do in fact absorb some degree of indoctrination at a very superficial level, and that the virtual absence of any serious counterarguments leaves them at this very superficial and unreflective mode of analysis. I think this is probably right--for instance, I am amazed at the shallowness of analysis that I hear from ostensibly educated students. Comments I hear about environmental issues, in particular, come to mind.There's something naive, even simple-minded about this (a seemingly persistent quality of Todd's thinking), and a discerning reader will probably notice it right away. The issue Todd is discussing in this paragraph is not the ideologically diversity of university professors, but of the ideas they present in their courses. But Todd doesn't present any evidence of a lack of ideological diversity in classroom material, and neither do any of the studies he and other conservatives cite. They only look at professors' political orientations. But professors' political orientations and class reading lists are not the same thing, and there is no reason why a liberal professor would not include conservative ideas in a course in which they would be relevant. Until someone produces data showing that course reading lists are heavily skewed toward liberal sources, even when conservative sources are available, or that professors are, more often than not, unfair to conservative ideas in their presentation of them to students (a distinct possibility, but not a possibility made inevitable, or even probable, by disparities in political orientation), this point of Todd's seems to be arguing past itself. It certainly doesn't provide a reason for working towards ideological diversity in academia.
UPDATE: I added as an update after my initial post "intellectual self-discovery" for students in response to a perceptive reader comment. I did mean to include this as well as part of this point--in addition to developing individual critical reasoning skills, it is also important to develop individual student intellectual skills to understand themselves and the world better as well as guiding ethical and character attributes. Obviously this requires students to wrestle with various ideas in coming to their own world views.
Unfortunately, Todd merely repeats this argument for the third goal (responsible citizens, and all that), writing:
It seems to me that it is imperative that students be exposed to all viewpoints about the world and to learn to evaluate the truth and resonance of competing world views. Living together as citizens in a free society, and having the kinds of connections and conversations that make that possible, requires developing a depth of understanding that cannot be created in an atmosphere of one-sided intellectual orthodoxy. It is a pretty short road from the impoverished discussions in modern universities to the idiocy of Michael Moore and red v. blue America. I don't pretend that American political discussion was ever that exhaulted [sic], but surely we used to hold educated people to a higher standard of discourse then we see today, especially on university campuses? I personally would add to this that as part of educating free and responsible citizens we should make sure students understand the intellectual and historical foundations of the western world, but I recognize that this is a more controversial proposition.Once again, Todd is assuming, without any objective evidence, that disparity in political orientation is identical with, or directly and invariably causes, disparity in classroom material. (Note that there can be classroom disparity, due to the availability of quality material for example, even without there being a disparity in the political orientation of professors -- the two really are mutually exclusive.) Sure, Todd has some anecdotal evidence, from his own experience, like every conservative seems to. But I can tell you honestly that I had at least two professors as an undergraduate -- one in political science, and one in philosophy -- who were heavily biased toward conservative ideas in their teaching. Of course, that's 2 out of almost 60(yes, I took about 180 of coursework; I was a nerd on a two-degree track), most of whom (if we believe the studies) were liberal, but who showed no bias in their teaching. So Todd, like so many before him, has left us without a real argument for diversity among professors. Instead, he's argued for the sensible position that students should be exposed to a wide range of ideas, but he can provide no evidence that they are not.
In fact, as Leiter hints in his response, Zywicki's argument (for diversity in the classroom, not in the ranks of the professors who teach in them) may actually undermine his own position. The key is to have a significantly diverse collection of scholarly ideas. Many of the scholarly ideas that professors teach in their courses were produced by other university professors, and thus it is important that, across all universities (in the world, not necessarily in the United States), there be a wide range of viewpoints (not just political, but with Todd, we have to keep things simple, and what's simpler than considering an incredibly broad issue unidimensionally?) among professors, so that a wide range of ideas are produced for instructors to use. But this doesn't mean that we need intellectual diversity at each individual university, and it certainly doesn't imply that we should require it by law. It may be that, as Leiter claims, scholarship advances more rapidly when several like-minded thinkers are working closely together. I know that in the sciences, that is often the case, because it facilitates productive cooperation on research. In cognitive science (I don't know about other sciences), this has led most universities to concentrate on hiring people studying similar things from similar perspectives. They can still teach about a variety of ideas, but when they do the research, they start from their own position.
So, Zywicki's arguments fail, but might there be other reasons for promoting diversity in academia? My feeling is that in the most departments (the natural sciences, most of the social sciences, applied fields like engineering and medicine, and even in many humanities departments), political orientation is completely irrelevant irrelevant. There is absolutely no reason to worry about diversity on this dimension. In departments where political orientation may be relevant, such as political science, how much would diversity improve education? To what extent would students come away with a more diverse education, if they studied at a university at a more politically diverse institution? I doubt anyone can answer that question effectively now, and until someone goes out and gather the relevant data, all of the posturing by conservatives seems misguided to me.