The year that dates his autobiographical letter to Campanus saw the publication in Strasbourg of Franck's best-known literary work: _Chronica, Zeitbuch und Geschichtsbibel_ ("A Universal Chronicle of the World's History from the Earliest Times to the Present").[7] It has { 50} often been pointed out that much of the material of this great Chronicle is taken over from earlier Chroniclers, especially from the Nuremberger Schedel, and it is furthermore true that Franck's _Book of the Ages_ contains large tracts of unhistorical narrative, set forth after the manner of Chroniclers without much critical insight, but the book, nevertheless, has a unique value. It abounds in Franck's peculiar irony and paradox, and it unfolds his conception of the spiritual history of the race, under the tuition of the Divine Word. At the beginning are patriarchs living in the dawn of the world under the guidance of inward vision, and at the end are saints and heretics, whom Franck finds among all races, bravely following the same inward Light, now after the ages grown clearer and more luminous, and sufficient for those who will patiently and faithfully heed it, while the real "heretics" for him are "heretics of the letter." "We ought to act carefully before God"--this is Franck's constant testimony--"hold to God alone and look upon Him as the cause of all things, and we ought always in all matters to notice what God says in us, to pay attention to the witness of our hearts, and never to think, or act, against our conscience. For everything does not hang upon the bare letter of Scripture; everything hangs, rather, on the spirit of Scripture and on a spiritual understanding of the inner meaning of what God has said. If we weigh every matter carefully we shall find its true meaning in the depth of our spiritual understanding and by the mind of Christ. Otherwise, the dead letter of Scripture would make us all heretics and fools, for everything can be bedecked and defended with texts, therefore let nobody confound himself and confuse himself with Scripture, but let every one weigh and test Scripture to see how it fits his own heart. If it is against his conscience and the Word within his own soul, then be sure he has not reached the right meaning, according to the mind of the Spirit, for the Scriptures must give witness to the Spirit, never against it."[8]