 In short, historians conceptualize, describe, contextualize, explain, and interpret events and circumstances of the past. They sketch out ways of representing the complex activities and events of the past; they explain and interpret significant outcomes; and they base their findings on evidence in the present that bears upon facts about the past. Their accounts need to be grounded on the evidence of the available historical record, and their explanations and interpretations require that the historian arrive at hypotheses about social causes and cultural meanings. Historians can turn to the best available theories in the social and behavioral sciences to arrive at theories about causal mechanisms and human behavior; so historical statements depend ultimately upon factual inquiry and theoretical reasoning. Ultimately, the historian’s task is to shed light on the what, why, and how of the past, based on inferences from the evidence of the present.