JOHN of KASTL. — Around 1400 prior of the abbey of Kastl, Benedictine (diocese of Eichstätt), he is attested by manuscript evidence as the author of the following works:
De adhaerendo Deo (attributed to Albert the Great until Grabmann discovered its true author); Spiritualis philosophia de suiipsius vera et humili cognitione; De natura, gratia, gloria ac beatitudine in patria; De lumine increato; Expositio in Regulam s. Benedicti; Ctenodium religiosorum;
Expositio psalmorum in generali; he was also the author of short treatises, some of which in the form of prayer. Trithemius mentions only the Expositio in regulam among the aforementioned, but recalls others. Only the De adhaerendo Deo has been printed. In this work J. shows himself to be a good connoisseur of the epistemology, metaphysics, doctrine of grace, and mysticism of Aquinas, and in his conception of spiritual life he is faithful to tradition. Through asceticism (the reform of Kastl) and self-knowledge the foundation is laid for an intimate veneration of the humanity of Christ, especially of His sacred stigmata.