Read Descartes. He asserts outright many times that he is proving that God (the order in Nature) exists, and that we can rely on the fact that God (the order in Nature) will always exist and always has existed. He outright says this is an axiom, a fundamental observation upon which we can base all science. logic, and mathematics. Before he died, he said nothing can be known for certain except what can be deduced which is always dependent on what you assume is true axiomatically. So, without God, all deduction collapses. All science collapses.

As he sums it up "I think therefore I am." Existence itself depends on God (the order in Nature) as can be perceived by the brain (which can never see all the order in Nature because we can always see more order than we saw before).

He did not, back then, discuss "hypotheses" as we know them today.