No, the idea that Earth was the center of the universe was not based just on religious belief. The Ptolemaic theory, constructed by Ptolemy (90–168 C.E.), did a fairly good job of describing both sensory experience and astronomical records and calculations that went back several thousand years. The movements of the heavenly bodies, which were themselves believed to be made of different and more ethereal stuff than Earth, could be more or less accurately predicted, according to this theory. It was also in accord with the existing natural philosophy that everything was made up of earth, water, fire, and air, in an ascending hierarchy. However, Ptolemy’s assumption that Earth was stationary required a postulation of 80 “epicycles” to “save the appearances,” which means that new complicated postulations were necessary to make the theory match observations.