Altenstaig, Johannes (c.1480–c.1525), German humanist and anti-Reformation publicist. Altenstaig was probably born in Mindelheim around 1480. The earliest affirmed date of his life is 1497, the year of his matriculation at the University of Tübingen, where he prepared for a life of teaching and scholarship. Under the sway of the humanist faculty there, he adopted an essentially moral concept of Christianity and joined with the “moderns” to rescue classical Latin from the corruptions of contemporary usage.
An Augustinian Eremite, Altenstaig taught philosophy and theology at his order's school in Polling from 1509 to 1512, when he was called to Mindelheim as chaplain to the Saint Sebastian Brotherhood. He also taught Latin at the Augustinian monastery there. He was a friend of Johann Eck and enjoyed the confidence of Bishop Christoph von Stadion, under whose auspices he conducted a visitation of the Augsburg diocese in 1518.
Thoughtful and peaceable, Altenstaig viewed Luther's Reformation with fear and dismay. Although a sharp critic of the church hierarchy for its inattention to clerical avarice and pastoral neglect, Altenstaig shrank from any break with Catholic tradition and Authority. His writings against the Reformation—including Ain nutzlich vnnd in hailiger geschrifft gegründte vnderricht (Augsburg, 1523) and Von der Füllerey ein müter aller vbel vnd laster (Strasbourg, 1525)—dealt primarily with external rather than deeper religious/theological points of contention and warned the common people against the dangers of following “false prophets” who held only to the Bible and denied man's free will to choose good over evil.
While calling for reforms, Altenstaig remained convinced of the spiritual benefits of a well-ordered monastic life. This, he believed, should be dedicated to teaching and theological scholarship, the key to moral reform and God's greatest gift to mankind.
Altenstaig's scholarly treatises such as Opusculum de amicitia and De felicitate triplici, both published at Hagenau in 1519, were based primarily on maxims and reflections culled from his reading in classical and Christian literature. Neither a profound thinker nor an innovator, he may be categorized among those who, while staying their ground, gave substance to the cause of Catholic reform.