Heliocentrism and Epistemology

Descartes' thought experiment can be interpreted as aiming at improving the Medieval Proofs of the Existence of God--by proving that I Exist, thereby upgrading an argument in which that proposition is the premise, from valid to sound.  It can also be interpreted as an attempt to reckon with the Epistemological implications of Heliocentrism, which, given the fates of Bruno and Galileo, is likely of paramount concern to him.  Tending to support this interpretation are the contents of his works surrounding the Meditations, including the publication of his advocacy of Heliocentrism almost immediately after.  But if so, his thought experiment misdiagnoses the Epistemological problem involved.  For, the error of the cognitive basis of the now discredited Geocentrism--the perception that the Sun is in motion while the Earth is at rest--is not that it is a dream, an hallucination, a deception, etc.  It is that some sense data have been misinterpreted due to a faulty inference, i. e. that it is the Sun, not the Earth, that is in motion as its apparent location in the sky changes.  Plainly, furthermore, improving the proofs of the Existence of God, the ground in the Meditation of renewed confidence in external perception, does not correct the perceptual error that is at the basis of Geocentrism.  Conversely, what that error illustrates is that if any sense datum in his thought experiment is dubious, it is because it is incomplete, not because it is a fabrication of some kind.  For example, another sense datum, i. e. the feeling of his finger as he sticks it in the apparent fire, would likely undermine the hypothesis that the fire does not in fact exist.  In other words, Heliocentrism tends to support a Comprehensiveness, rather than a Correspondence, theory of Truth. So, the Meditations are more effective as a Theological exercise than as an Epistemological one.