In 364 the German Schoolman, Henry Hembuche of Langenstein, or as he is more frequently called, Henry of Hesse, wrote an extremely odd treatise entitled On the Reprobation of Eccentrics and Epicycles (De reprobatione ecentricorum et epiciclorum) in which he attempted to refute Ptolemaic astronomy. We can be confident of the date, 1364, since Henry himself tells us that he is writing in that year. At that time Langenstein had been an M.A. at Paris for about a year, and was teaching in the arts faculty while pursuing the studies which were ultimately to bring him a doctorate in theology.