Paracelsus (1493?1541) spoke in various contexts about the multi-facetted topic of images. As a radical lay theologian, he wrote in the spirit of the Reformation attacking the Roman Church’s use of images and outlining the power of faith. As a natural philosopher andphysician, he composed a tract on images which was intended not to instruct readers in the aesthetic enjoyment of images, but to deploy their “power” and their “virtue” to explore the world and gain salvation. In his main work Astronomia magna , he integrated his ideas of the efficacy of images in an encyclopaedic scientific programme and laid out his expectations of the true artist.