What idea of the geocentric model of the solar system was most contested by some philosophers

The most contested idea of the geocentric model of the solar system, particularly by philosophers and early scientists, was the notion that the Earth was the center of the universe and that all celestial bodies, including the Sun and stars, revolved around it. This model, primarily formalized by Claudius Ptolemy in the 2nd century AD, relied on a complex system of deferents and epicycles to explain the observed motions of the planets.

Philosophers and astronomers like Aristarchus of Samos, and later figures during the Renaissance such as Copernicus, Galileo, and Kepler, challenged the geocentric view by proposing heliocentric models, which positioned the Sun at the center of the solar system. These ideas were often resisted due to their implications for traditional views of cosmology, religion, and the nature of the universe, as well as the lack of observational evidence for heliocentrism at the time. The transition from a geocentric to a heliocentric understanding was a significant moment in the history of science, leading to profound changes in our understanding of the universe.