Consider understanding Calvin's epistemology before pontificating.
"I call that knowledge, not what is innate in man (pure rationalism) nor what is by diligence acquired (empiricism), but that which is delivered to us by the Law and the Prophets." (Commentary on Jer. 44:3)
If you're a self-professing Calvinist who's allergic to the phrase "the light of nature," then you likely haven't read Calvin's own (positive) comments on "the light of nature."