Or at least how would you describe someone like that?
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
OK, I was coming at it from an early Christian, Hellenistic POV. Gnostic, as in the 'Divine Spark' philosophy. I have never read much Jung, I know the name, but nothing about his philosophy. My knowledge of the 19th century European philosophy is woefully lacking. Thanks for sharing - I'll look more into this.
Btw, I was the one who mentioned Stoic philosophy. Thanks for the compliments!
Maybe 'Agnostic' instead of 'Gnostic'? Definition of agnostic is (in a nonreligious context) having a doubtful or noncommittal attitude toward something. while gnostic is relating to knowledge, especially esoteric mystical knowledge.