What's the correct correct term for somone who doesn't buy into party politics or form an affiliation with any one belief system but takes everything on its own merits?

Gnostic means "to know from within". It is basically the process of accumulating information through the trivium (grammar, rhetoric, and logic). This is probably a slant I have developed because I came across Gnosticism through Carl Jung. I found a bit of info pertaining to his views on Gnosticism. I think a Jung has built a bridge potentially between agnosticism and Gnosticism. Someone else here mentioned Stoicism and I think that is pretty darn close to the truth of OP's question. > Jung saw the Gnostics not as syncretic schools of mixed theological doctrines, but as genuine visionaries, and saw their imagery not as myths but as records of inner experience. He wrote that "The explanation of Gnostic ideas 'in terms of themselves,' i.e., in terms of their historical foundations, is futile, for in that way they are reduced only to their less developed forestages but not understood in their actual significance." Instead, he worked to understand and explain Gnosticism from a psychological standpoint. While providing something of an ancient mirror of his work, Jung saw "his psychology not as a contemporary version of Gnosticism, but as a contemporary counterpart to it." https://en.wikipedia.org/wiki/Gnosticism_in_modern_times#Carl_Jung