Just a quick and dirty intervention here. Matt, I have to take exception with a couple of your points. First, on whether history is or isn't a social science - that's a matter of perspective, as much a function of whether one believes scholarly output should be readable literature with some sort of narrative backbone, rather than esoteric code generated for a select few initiates. Your assertion ducks important philosophical discussion of rigorous application of method, objectivity in scholarship, and epistemological assumptions about the nature of empirical research - discussions that apply equally well across disciplines.

On to subjects more central to our discussion. In explaining to your students the nature of the "expert", you cite two types: the scholar and the journalist, and impute depth and leisure as the mark of one, and superficiality and time constraints as the mark of the other. Again, unfair. We've all heard of scholars who endlessly circulate retitled papers to pad their CVs, or who take shortcuts to increase measurable publication output. These, too, result from professional pressures. Likewise with journalism, which really depends on the type of journalism we're referring to. Feature journalists, for example, are expected to go deep on their subjects as a matter of course.

This, though, brings me to an important point that I think is relevant to Brian Williams role in the Hamdan case: the distinction between expert and witness, and in particular, the role of the latter in knowledge formation, creating perceptions of practice, and ethical conduct. I was struck by the fact that Brian, serving as an expert witness, then turned around and acted as a witness to the entire process by drafting his account of it all. This dual track narrative potential had me wondering about the implications of an an expert called upon to bear witness within the legal process, based on a lifetime of witnessing - through long, meticulous study of a subject - that becomes a resource for legal processes and informs its subsequent public narrative.

If witnessing is part and parcel of how experts develop their expertise, then one wonders at the professional academic, for example, who calls two weeks each summer "field work", while the journalist lives and breathes the daily experiences whereof he speaks. Lived experience isn't the only form of witnessing, of course. There's a plausible argument to be made that witnessing and observing are distinct acts with distinct consequences and outcomes (which in turn touches on potentially thorny moral questions surrounding bystanders and participants). Witnessing certainly isn't the only path to expertise. But it's an important one. There's been some interesting literature in recent years, for example, that touches on the varying narrative potential of international criminal court proceedings, in historical and legal terms.

What do the disciplines have to say about this? A question for another debate, perhaps.