If IR is about real-world events out there, traditionally the relations between states, then why should we pay attention to philosophy?
Well, I think that the thing that philosophy does for us—and by ‘us’ I mean IR scholars broadly understand, those of us who are in some sense interested in global affairs—we’re interested in producing knowledge of global affairs that is in some sense valid. I think that’s a really important qualifier because there are lots of people that are interested in global affairs primarily so they can go out and change it. I have lots of students like this, who want to study (for example) what’s going on in sub-Saharan Africa so they can go out and improve people’s lives, which is excellent work and they should go do that, and if they do it well they’ll make an excellent near-term impact. But if they’re interested in knowing things and generating knowledge about global politics that is in some sense valid, that’s another matter. A lot of things are packed into the phrase ‘in some sense’ because there’s diversity in things can be valid. And I don’t think this is what philosophers find useful in the philosophy of science. What the social sciences should find useful in the philosophy of science, or in philosophy in general, is that the exercise of elaborating the logical structures and the preconditions of the assumptions of particular modes of knowing can provide some useful clarity for those of us that are mostly engaged in our everyday work in grappling with the stuff of the social world. Philosophy allows you to pull back from that stuff a little bit, reflect on exactly what it is that you’re doing. There’s a way in which the study of philosophy or the reading of philosophy can serve as a moment for methodological and theoretical reflection.
Now I know this is not what philosophers of science think they’re doing, because they’re not particularly interested in providing moments of reflection for IR scholars or other social scientists. Ok, fine, but we’re not in philosophy, we’re here in IR, so we have to just sort of operate from where we are. On that basis I think that it’s useful to read philosophy—it’s useful for any sort of social-scientific field, but it’s particularly useful for IR to have that kind of moment of reflexivity—methodological reflection—precisely because in our very subject matter itself, which is global, there are diverse answers to those questions. This is not to say that we necessarily have to always adopt the perspective of people we study or to say that we have to ignore the perspective of people we’re studying, but it’s to say that we should need to probably confront the question of what we’re doing when we make sense of the world and how it relates to what the people we’re studying are doing in making sense of the world.