But the capital, so conspicuous for its refinement and its great antiquity, was even more venerable for the religious traditions which invested it. It was here that the god Quetzalcoatl paused in his passage to the coast, and passed twenty years in teaching the Toltec inhabitants the arts of civilization. He made them acquainted with better forms of government, and a more spiritualized religion, in which the only sacrifices were the fruits and flowers of the season.[192] It is not easy to determine what he taught, since his lessons have been so mingled with the licentious dogmas of his own priests and the mystic commentaries of the Christian missionary.[193] It is probable that he was one of those rare and gifted beings who, dissipating the darkness of the age by the illumination of their own genius, are deified by a grateful posterity and placed among the lights of heaven. It was in honor of this benevolent deity that the stupendous mound{*} was erected on which the traveller still gazes with admiration as the most colossal fabric in New Spain, rivalling in dimensions, and somewhat resembling in form, the pyramidal structures of ancient Egypt. The date of its erection is unknown; for it was found there when the Aztecs entered on the plateau. It had the form common to the Mexican _teocallis_, that of a truncated pyramid, facing with its four sides the cardinal points, and divided into the same number of terraces. Its original outlines, however, have been effaced by the action of time and of the elements, while the exuberant growth of shrubs and wild flowers, which have mantled over its surface, give it the appearance of one of those symmetrical elevations thrown up by the caprice of nature rather than by the industry of man. It is doubtful indeed, whether the interior be not a natural hill; though it seems not improbable that it is an artificial composition of stone and earth, deeply incrusted, as is certain, in every part, with alternate strata of brick and clay.[194] In the teacher himself they recognize no less a person than St. Thomas the Apostle! See the Dissertation of the irrefragable Dr. Mier, with an edifying commentary by Señor Bustamante, ap. Sahagun. (Hist. de Nueva-España, tom. i., Suplemento.) The reader will find further particulars of this matter in the essay on the Origin of the Mexican Civilization, at the end of the first book of this history.