A group of peoples whose home is Asia and Africa, reputed descendants of Sem, son of Noe. In historic times all western Asia, with the exception of Asia Minor, was Semitic, and philologically the race is divided into four chief groups: Babylonian-Assyrian, Chanaanite, Aramaic, and Arabian. The tribes which inhabited these territories show in their language, traits, and character a sharply defined individuality which separates them distinctly from other peoples. Their languages are closely related to one another, being dialects of a single linguistic group, the purest form being found in Arabia; and from this and other circumstances it has been concluded that Arabia is the original home of the Semitic race. The Semites have contributed much to civilization, e.g., to Babylonia are traced the beginnings of astronomy and perhaps mathematics, and the division of time by weeks, and to Phenicia the distribution of the alphabet.