Doubt, Mathematics, God

Descartes' contention that even the simplest Mathematical proposition is uncertain, because it could be the product of demonic deception, seems explainable in one of two ways.  First, that it is possible that all Mathematical propositions are fictions, or, second, that there exists some realm in which Mathematical relations are other than they have always appeared to be.  However, as Descartes acknowledges, that a mathematical proposition is merely imaginary does not falsify it, so, what it asserts is no less certain in that scenario.  Furthermore, the existence of a realm in which there subsist Mathematical relations that are other than have always been represented by a human being, is more implausible than whatever grounds for qualms that Descartes has about those representations, and, so, hardly suffices to even give pause about them.  So, his doubt of Mathematics seems itself a specious contrivance, perhaps designed to promote the questionable Theological thesis that God is more powerful than Mathematics, i. e. can ultimately override its propositions.