Revising historical accounts when new evidence comes to light or when old evidence begs to be reconsidered is surely one of the major tasks of the scholarly historian. The practitioner should ideally possess the ability to unravel the past before our eyes in a clear and unbiased fashion, both at phenomenological and causal levels. Some would argue that a scholarly historian can not, any more than can a microbiologist investigating the minuscule parts of an organism, detach the circumstances of his or her act of observation from the object itself. In this view, historians' accounts of the past are subjective narratives by default if not by design. Narratives can, it might be argued, be disproved—but factuality cannot be proved. Yet even this is not as straightforward as it might seem: the best one can do is simply to accumulate narratives, not with a view to displacing older with newer ones, but to develop a larger or, pointedly in this context, more useful, picture of reality.Sari Nusseibeh is a visiting fellow at the Radcliffe Institute for Advanced Study, Harvard University (snusseib@ radcliffe.edu), and professor of philosophy, al-Quds University, the Arab University of Jerusalem, of which he was appointed president in 1995.