I'm a pretty interdisciplinary person. I've always been the type who would rather know a little bit about a lot of topics than a lot about a few topics--jack of all trades and master of none, if you will. Obviously I've had to focus somewhat as I've gotten more involved in academia, but philosophy is still an incredibly interdisciplinary field of study. It always has been--'philosophers,' traditionally, have played the roles of scientist, literary critic, playwright, mathematician, and a whole host of others--and though recently (i.e. within the last 200 or so years) our province has shrunk a bit, philosophers still commonly call on knowledge from several different areas of academia in the course of their work. This is particularly true in philosophy of mind, I think, which is increasingly overlapping with cognitive neuroscience, a rather new interdisciplinary program at many universities. Still, even if you're working in Medieval philosophy, the ability to synthesize across disciplines is vital. There are, however, some pretty troubling issues in various interdisciplinary programs, as an email I got today from a friend of mine pointed out.
When I was at Berkeley, I double-majored in philosophy and Peace & Conflict Studies (PACS). I've always been pretty interested in human rights, social justice, nonviolence, and similar issues, and this relatively unique program at Berkeley seemed to be a perfect fit when I enrolled as a Freshman. I quickly discovered, though, that the department was fraught with problems--the most severe of which, I think, was a general resistance to critical examinations of foundational assumptions (e.g. that violence is wrong), and an almost religious fervor in defending those assumptions. I'm not saying that everyone in the program was like this--I met some really great people in the PACS program, and was greatly impressed with at least some of the professors--but it was enough of a problem that I noticed, and apparently I'm not alone. I got an email today from a friend in the program saying that one of the more popular courses ended in "crying and a shouting match," as two contingents of the course (one of whom apparently thought that the professor was acting as a western apologist) clashed over how the material was being presented.
I definitely have my suspicions as to whom this altercation involved--I suspect it was the same group I repeatedly clashed with while I was there--but that's not really my point here. I think these kinds of clashes are going to become increasingly common in interdisciplinary programs like PACS, and I think that they're necessary growing pains that departments like this are going to have to go through before they'll be taken seriously by other academics.
The last twenty years or so have seen the emergence of a plethora of "new" academic programs, most of which end in the word 'studies.' Peace & Conflict Studies, Gender Studies, and African-American Studies (to name a few), have all arisen and/or started to become more popular in the last two or three decades. In the beginning, programs of this sort were occupied primarily by "true believers"--that is, people who had a strong (and often orthodox) view on the discipline--and were often pretty homogeneous as a result. PACS-style programs, for instance, have been traditionally attended by far-left leaning individuals interested primarily in activism and working for social justice.
This homogeneity, I think, is one of the reasons that other academics have a hard time taking (for example) PACS seriously. I was talking to John Searle once during his office hours, and mentioned offhand that I was double-majoring in PACS along with philosophy; he was agast. I can't remember his exact words, but they were something like "I always thought majors ending in the word 'studies' did anything but that." He was willing to listen to what I had to say, and I think he accepted some of the points I made about the legitimacy of studying war and violence specifically, but that kind of perception is very wide-spread in academia--as I said, I think that the traditional homogeneity of these disciplines is at least partially to blame. Academia is based, at least in large part, self-criticism and peer review--physics, philosophy, and other "traditionally" academic disciplines have advanced primarily through reasoned criticism from within: the fact that astrophysics has come as far as it has is directly related to the fact that not everyone accepted the belief that the Sun revolved around the Earth as dogma. Similarly, the fact that philosophers, on the whole, no longer accept Logical Behaviorism is related to the sustained and reasoned criticism of the doctrine that other philosophers made throughout the 60s and 70s. In short, a diversity of opinions within a single department is a good thing.
A lot of academics, I think, see the traditional insularity of departments like PACS and think to themselves "They all think more or less the same thing, so why should I listen to them;" philosophers in particular tend to eschew dogmatism. Because of this, I think we should welcome the current trend of breaking up the monotony of "-studies" programs. Even in my four years in PACS at Berkeley, I saw a truly enormous influx of students to the major, which naturally meant a huge influx of opinions. A lot of the people in my classes disliked me because I was unwilling to take assumptions as unquestioned axioms, but toward the end there was a small (but growing) minority of people who shared my desire to make the PACS major a bit more rigorous.
As this trend continues--and as "true believers" are replaced by people who are interested in but critical of the subject--I think we can expect majors like "Peace Studies" to begin to gain respectability, but not without growing pains. The incident my friend alluded to in his email is a manifestation of these growing pains, it seems to me--people who are in the program only to hear their own opinions repeated back to them are naturally going to resent those who seek to bring serious discourse into the classroom; dogmatic people don't like to question their dogma. Still, though, I think in the end the rewards will be worth it: interdisciplinary departments will, at last, begin to have the same recognition and respect shown to them that philosophy, English, biology, and physics do. All we need to do is keep arguing with ourselves.