SOURCE: "Physical Geography" in The Makers of Medieval Muslim Geography, Renaissance Publishing House, 1995, pp. 153-84.

[In the following excerpt, Kazmi contends that al-Bīrūnī combines popular, historical, and religious beliefs with scientific observation, particularly in his studies of the hydrosphere and atmosphere.]

Alberuni had a deep and clear understanding of several problems of physical geography. There are three basic tenets of his physical philosophy which are at the root of all his naturalistic theories. The first and, perhaps, the foremost, is his conception that change is the law of nature and that the natural face of the earth is only transient. His concept of the non-permanency of earth's features, major or minor, global or regional, has a far reaching significance as his ideas regarding certain phenomena of the earth such as erosion and denudation, upheaval and subsidence, eustatic and isostatic adjustments and so on rest on this...