Demographic: Here is yet another indication that Mormon’s description is more literary than literal. He has a group of Nephites leave the land of Zarahemla, and in some period of time “cover the face of the whole earth, from the sea south to the sea north, from the sea west to the sea east.” Even allowing that he is describing the conditions of his own time, he gives only a period of four hundred years for this people to have multiplied to the point where they “cover the face of the whole earth.”
While the people in the land northward most certainly did cover the whole face of the earth in Mormon’s time, it is impossible that they all derived from this smaller group of dissident Nephites. Mormon is taking literary license with history so that he may link the dissident Nephites with the events of the last days of the Nephites, which will be heavily influenced by these people from the land northward, a people that Mormon will refer to as the Gadianton robbers of his own day.
Geographic: Mormon gives us a set of terms here that we might be tempted to see as geographic references. He notes that these people in the land northward cover the whole face of the earth, “from the sea south to the sea north, from the sea west to the sea east.” There are four seas listed, and they are in each of the direct cardinal points. Rather than see this as a geographic reference, we should rather see this as an expansion of the idea of the “whole face of the earth.” Mesoamerican peoples symbolically centered themselves in a universe that existed inside the four directions. (David Freidel, Linda Schele, Joy Parker. Maya Cosmos: Three Thousand Years on the Shaman’s Path. William Morrow and Company, Inc. 1993, p.126-7).
Significantly for Mormon’s expression, the later Aztecs conceived of their world as completely surrounded by water. Their name for the earth was Anahuac or a land ringed by water: “Completing their division in the horizontal plane, toward the four corners of the world, they conceived of this great disk of the world as surrounded by water.” (Miguel Leon-Portilla. La Filosofia Nahuatl. Universidad Nacional Autonoma de Mexico, Instituto de Investigaciones Historicas. Mexico, 1974, p. 113.)
In this context, we should see Mormon’s description as a further definition of what constitutes the whole world, rather than a definition of geographic location. By specifically noting the four seas, Mormon surrounds the conceptual face of the land with the waters of the world, and emphasizes the tremendous extent of this “whole face.”