The decision of Nicolaus Copernicus (1473–1543) to propose a heliocentric system, remove the Earth from the center of the universe, and establish a relationship between the distances of the different planets from the sun and the amplitude of their orbits was based on mathematical reasoning and the weaknesses of Aristotelian-Ptolemaic system in this regard. Johannes Kepler (1571–1630) defended the Copernican theory by re-utilizing geometrical arguments from Plato’s Timaeus, and he also developed other theories (such as the elliptical form of the planetary orbits) founded on the geometrical structure that he attributed to the universe. Despite the fact that aspects of his method, and in particular the regressus, were essentially Aristotelian, Galileo Galilei (1564–1642) has been often described as a Platonist, insofar as Platonism endorsed a mathematical approach. Galileo denied the reality of the physical elements of the Aristotelian world and the theory of their natural movements, and replaced them with corporeal matter, whose properties and motions could be described in mathematical terms. Furthermore, by relying on new instruments such as the telescope, Galileo was also able to make new observations which revealed the imperfections of the supralunar world.  Galileo and the Copernican theory met with the resistance of the Church, but also of the universities, whose professoriate was not eager to renounce one of the central pillars of its teaching. On the other hand, the Tychonic system elaborated by Brahe, which attempted to conciliate the traditional Aristotelian-Ptolemaic cosmology with Copernicus, encountered support even among Jesuit scientists.