Cusanus's work De visione dei, at once a theoretical treatise on mysticism and a practical manuductio into it, stresses the cognitive element in an otherwise negative theology. It reveals the influences of Pseudo-Dionysius, Albert of Cologne, Eckhart, and possibly Ruusbroec (or at least that of his follower, Denys the Carthusian). It centres around the theme of seeing God which it identifies with being seen by Him. It features a Neoplatonic theory of form interpreted, however, through a very original Christology.