Abstract

The early seventeenth century had a great diversity of astronomical world system models hotly debated by the astronomers of the period. With hindsight, in comparison with Galilei, one cannot avoid noticing that the margravial astronomer Simon Marius held the wrong position. This article will show firstly that a reliable scientific proof for heliocentrism had not yet been accomplished and secondly, that Marius’s arguments were in good accordance with the empirical observations. In some areas, one would even like to call on him, not to take individual observations too “literally.” An examination of his research is not only a serious reconsideration of an underappreciated astronomer but also promotes an understanding of how the world systems were negotiated and how we progress toward certain knowledge.