There is a periodic need for a general survey and stock-taking in almost every field, but in the domain of the pre-Islamic history of Iran, to my knowledge, there has been little scholarly assessment of the picture of the past in light of changes wrought by new source materials. One important reason is that the sources for this history have increased considerably in the past few decades, and scholars have devoted the bulk of their time to the elucidation of these sources, with little time left for a study of their historical consequences. Another point which should be made is the difference between the requirements, on the one hand, for the work of ancient and medieval historians and, on the other hand, for that of modern colleagues. Historians of more recent times like to emphasize the homogeneity of the historical profession and the continuity of methods in the entire field. But in practice it is the classicist who, in our universities, concerns himself with ancient history. I mean by this one who is trained in the methods of textual analysis and the tools of the classicist, and it is the Orientalist or philologist who writes the history of the pre-modern Orient. Given the difficulties of ancient oriental languages and the need to gather source material from the archeologist, epigraphist, numismatist, and art historian, one can understand the great demands on these specialists who would write history. It is no wonder that the methods of the modern historian, evolved from work with an abundance of material and the need for comparison of various sources in evaluating a multitude of factors and roles played by individuals in a given situation, are of a somewhat different nature from those of the scholar who investigates the more distant past. The modern historian is dependent on the economist and political scientist for aid in reconstructing his story. This is the result, of course, of the differentiation and great expansion of knowledge in modern times. The disciplines become defined, and specialization is a necessity in view of the great mass of documentation. Before the advent of writing, archeology, history, and other disciplines are undifferentiated. With its invention, however, the process of ordering subjects and fields at once begins. With the increase of material remains, archeology, for example, divides into the history of architecture, with art, epigraphy, numismatics, the history of technology, and so on. This is inherent in the process of understanding.