When the new Star Trek film premiers next week, we can expect to see one of the beloved members of the regular Enterprise crew, Lieutenant Hikaru Sulu, portrayed as gay, by way of a scene in which he is “pictured with a male spouse raising their infant child.”

Unexpectedly, George Takei, who played Sulu in the original “Star Trek” series, has objected. This surprised everyone because Takei is gay and in recent years has been a vocal advocate for gay marriage. He objected out of loyalty to Gene Roddenberry’s original vision, in which Sulu was not gay and was even implied (somewhat vaguely) to be heterosexual: in one episode, he flirts with a space hippie and in another, he shows interest in a showgirl—though admittedly you could take that either way. I’m not counting the mirror universe Sulu, who makes a pretty aggressive pass at Lt. Uhura. But that’s the mirror universe, and everybody’s different there.

Takei recounts how he once quietly pressed Roddenberry to take on the issue of tolerance for homosexuality, but Roddenberry declined on the grounds that the show’s indirect commentary on racism and the Vietnam War had already tried the network’s patience with overtly political messages.

This was clearly a different era—and no, I’m not talking about different attitudes toward homosexuality. I’m talking about different attitudes toward using television shows and movies as vehicles for political and culture war propaganda, something that was frowned upon then but is now considered mandatory.

That’s what strikes me as really off-kilter about this way of approaching the issue in the Star Trek franchise. The series has never shied away from a humanistic message and a kind of old-fashioned liberalism, which it has sometimes worn a little too much on its sleeve. But the classic Star Trek approach was never anything so bland, concrete, and obvious as ticking off PC boxes.

(In the 1968 book The Making of Star Trek—which, um, yeah, I’ve read—I remember a story about someone writing in to complain about Sulu not getting romantic plot lines. Roddenberry and his staff wrote back, facetiously, to explain that they apportioned romances according to the ratios of naval tonnage allowed to America and Japan in the treaty that ended World War II. Like I said, it was a different era.)

The current mania for injecting gay characters into classic comic books, movies, and TV shows reflects an attitude that’s reminiscent of old Marxist Social Realism, which has been nicely summed up as the view that “the primary—the only, really—goal of…art was to educate the masses as to the ‘correct’ way of thinking.” Every work of art is expected to tick down a list of propaganda points meant to serve narrow, immediate political purposes.

While Star Trek sometimes had an agenda, its approach to that agenda was very different. It used a science fiction setting to create analogies and allegories for current events. Take that famous episode on racism, which portrayed two antagonists driven by a bitter, ancient racial hatred. The problem is that the Enterprise crew can’t see any difference between them, until the aliens point out that one of them is black on the right side of his body and white on the left, while the other is white on the right side and black on the left. It was not the most subtle allegory, but it invited us to wonder how aliens with very different physical characteristics might see us humans. Would we all look identical to them, and would they be equally mystified by ancient hatreds based on characteristics they barely notice?

The Star Trek franchise did eventually get around to dealing with the issue of homosexuality, in a far better and more interesting way than just making one of the characters gay. In the 1992 “Star Trek: The Next Generation” episode “The Outcast,” the crew of the Enterprise visits an androgynous alien race that long ago rejected the concept of gender—and who now consider gender preferences aberrant and dangerous, to be “cured” through some kind of advanced but malevolent-sounding psychological therapy. This all comes to a head when the super-masculine Commander Riker—this was after he grew the beard, mind you—brings out the woman in his alien counterpart. Here is the speech she delivers at the episode’s climax.

You can see the allegorical implications, but Star Trek at least did it in a clever way: turning the tables and asking us what we would think if heterosexuality and traditional gender differences were outlawed.

Oh, the irony, because it is in our own era of gay liberation that it has become a matter of dogma to reject the “gender binary” and to insist that we all fall on a “gender spectrum” of various degrees of androgyny, so we have ended up with a generation of young people raised to reflexively avoid acknowledging that there is any definite difference between men and women.

So there’s an idea for the next Star Trek movie: Star Trek: Beyond the Poe Horizon.

The point is that this was a much better, much more interesting way of thinking about the big issues. “The Outcast” came in the fifth season of “The Next Generation,” somewhere between “Darmok” and “The Inner Light,” which are generally considered the two best episodes the series produced. Star Trek had reached its artistic peak and demonstrated that it could deal with high-concept plot premises in a way that gripped the audience’s attention.

This was a better way of thinking about big issues because it involved actually thinking about them, not just ticking off a box for character representation.

The current mania for parasitically taking over existing characters and rewriting them to fit various quotas of race, gender, and sexuality reflects a collapse in the intellectual level of the left. The old liberals saw themselves as ostentatiously interested in big messages and big ideas and expanded horizons—even if they still wore some really big blinders. Today’s cultural left just stands for conformity to a set of very narrow, concrete rules.