Knowledge and belief
On the intellectual, ideological, and religious levels, although some diversity and certain elaborations occurred in some regions, there was a fundamental unity to the Meso-American area, the product of centuries of political and economic ties. The religion was polytheistic, with numerous gods specialized along the lines of human activities. There were gods for basic activities such as war, reproduction, and agriculture; cosmogenic gods who created the universe and invented human culture; and gods of craft groups, social classes, political systems, and their subdivisions. Gods were all-powerful and had to be constantly propitiated with offerings and sacrifices, a concept reaching its peak in personal bloodletting and human sacrifice. Certain gods, such as the god of rain (called Tlaloc in central Mexico), were found throughout the area. A fundamental concept was that of a quadripartite multilevel universe that, by 1519, had gone through five creations and four destructions. Meso-American religion heavily emphasized the astral bodies, particularly the Sun, the Moon, and Venus, and the observations of the movement of these bodies by the astronomer-priests were extraordinarily detailed and accurate. The major purpose of these observations was astrological, and the Meso-American priests had developed a number of time counts, or calendrical rounds, based in part on these observations. Two basic calendars, a 260-day divinatory calendar and one based on the solar year of 365 days, were found throughout the area.
One of the great intellectual achievements of Meso-American civilization was writing; in Postclassic times books were made from the inner bark of the paper-fig tree and used to record calendars, astronomical tables, dynastic history, taxes, and court records.
Religion was a pervasive force in Meso-American life, as the art demonstrates; and considerable surplus energy was devoted to it (e.g., temple construction, support of a numerous professional priesthood). Many writers have stated that the major focus of Meso-American culture was in this sphere. In fact, the contrast between Postclassic and Classic was in part based on the presumed even greater emphasis on religion in the art and architecture of the latter period.