  The first principle of necessary truth licensing inferences from signs of intelligence to intelligence pairs with another that states that the belief in other minds is also a first principle (EIP 6.5, 484). Reid knows well how these two work together (EIP 6.5, 511–12) and as a result he unambiguously foreshadows the epistemological parity argument to be found in Plantinga's God and Other Minds (1990).