The late Stanley Grenz used to make a distinction between the “modernism” of the original Star Trek series and the “postmodernism” of Star Trek: The Next Generation. (Here‘s one take on that distinction.) In the original series, the Vulcan Spock, though frequently ribbed for allowing a few cracks to show in his rational exterior, was a powerful, in-control character who got the others out of many a jam through rational deduction. In Next Generation, the android Data, though physically and intellectually powerful, spent many episodes playing the unintentional buffoon and trying to get in touch with what it meant to truly be human–emotions, sense of humor, and all.
Grenz suggested that this difference between Spock on the original series and Data on Next Generation represented a shift in the valuation of human reason from modernity to postmodernity–from the implicit modernist faith in the omnicompetence of reason to the postmodern repudiation of reason as ultimate solver of all problems.