 An example can be found in the work of an author already mentioned: Nicholas of Poland, the radical medical empiricist of Montpellier. In his Antipocras Nicholas claims that although the presence of a divinely given power in the most humble of objects cannot be proven by reason, it “is made evident by its effect” (hoc patet effectu) (Nicholas of Poland Ant. ll. 202–3). In this respect Nicholas seems to have been influenced by another work more closely associated with magic, the De mirabilibus mundi. This states that there are “certain effects manifest to the senses to which we can assign no reason,” as well as effects known only by way of reason. The marvellous powers of natural objects belong to the former category, which are known by way of practical experience (per experientiam) (Ps-Albertus PA-DM para. 49–50). While this work was falsely attributed to Albert the Great (ca. 1200–1280), Albert himself adopts a similar line when defending the mysterious powers of certain stones: these, too, are known “most convincingly by experience,” although they lack a scientific explanation (A-DM 2.1.1).