In considering authorities upon American antiquities, one thing should be especially observed: one should be upon his guard against the credulity and bias of the early writers; and equally upon his guard against the skepticism and bias of the more modern ones. The former, living in an age of superstition and credulity, and having special interests to serve, would have us believe too much; the latter, living in an age super-critical and doubting, would have us believe too little. There is no doubt but what the Spanish writers connected with the conquest of America colored their narratives to give importance in the eyes of their countrymen in Europe to the events with which they were associated; and they likely exaggerated whatever had such a tendency. Hence greater empires, more formidable armies, and more imposing civilizations than really existed in America at the time of the conquest, were described. So with the missionaries who accompanied the first European expeditions and those who immediately followed them. They sometimes very likely saw analogies between the Christian faith and some of the traditions and superstitions of the natives where none existed. So closely did some of the native traditions and ceremonies resemble Catholic Christian dogma and rites that the over-zealous priests came to the conclusion that the "devil" had in America counterfeited some parts of the Christian religion and intermixed it with the native paganism, the better to encompass the damnation of the natives and hinder the progress of the Christian religion. This led to the destruction of many Aztec manuscripts which were regarded by some of the priests as works on magic, and in other ways were supposed to uphold the idolatry of the natives. This idea strongly impressed the first archbishop of Mexico, Don Juan de Zumarraga, [23] who from a number of cities caused large quantities of the native manuscripts to be collected and destroyed. The collection from Tezcuco was especially large, since--as Prescott describes it--Tezcuco was "the great depository of the national archives." The archbishop caused these collected manuscripts "to be piled up in a 'mountainlike heap,'--as it is called by the Spanish writers themselves--in the market place at Tlateloco and reduced them all to ashes. * * * The unlettered soldiery were not slow in imitating the example of their prelate. Every chart and volume which fell into their hands was wantonly destroyed: so that when the scholars of a later and more enlightened age anxiously sought to recover some of these memorials of civilization, nearly all had perished, and the few surviving were jealously hidden by the natives." [24] And thus was destroyed materials which might have gone far towards solving the mystery that enshrouds the people and civilization of ancient America.