How we cite our quotes: All quotations are from Star Trek IV: The Voyage Home.
Quote #1
SPOCK: If memory serves, there was a dubious flirtation with nuclear fission reactors resulting in toxic side effects.
The first aspect of our world that gets criticized as "primitive" is nuclear energy. By talking about this technology as a specific historical phenomenon that came and went, Spock shows us that our current era is a mere blipon the historical radar.
Quote #2
SULU: San Francisco. I was born there.
MCCOY: It doesn't look all that different.
San Francisco is an important city in the future—it's the headquarters of the Federation. The crew knows the place well. But although it might seem similar now, our crew members are in for a big surprise.
Quote #3
KIRK: Many of their customs will doubtless take us by surprise. It's a foregone conclusion that none of these people have ever seen an extraterrestrial before.
Spock responds to Kirk's statement in the most amazing way possible—by ripping off a piece of his robe and fashioning it into a headband, which he uses to hide his pointy eyebrows and ears. It's actually a good look. That being said, Spock's physical features will be the least distressing thing about him to this primitive world.
Quote #4
KIRK: This is an extremely primitive and paranoid culture.
We wanted to argue against this at first, but then we looked at the news.
Quote #5
MCCOY: It's a miracle these people ever got out of the 20th century.
KIRK: They're still using money. We've got to find some.
In Star Trek's vision of the future, money doesn't exist. At all. As a result, Kirk and company are wholly unfamiliar with how to function in a society based on the exchange of money. More than that, however, they see it as some arcane system that provides little value to society. It's hard to disagree…
Quote #6
KIRK: You mean profanity. That's simply the way they talk here. Nobody pays any attention to you if you don't swear every other word.
Though the punk rocker scene is a tad preachy, it reveals why the crew of Enterprise sees our time period as primitive. Think about what aliens would think if they looked at Twitter. Would they think that we're a nice species? No way. In the same way that we look down on the barbaric customs of our past, people of the future will no doubt see us as rude, crude, and uncivilized.
Quote #7
MCCOY: You realize, of course, if we give him the formula, we're altering the future.
SCOTTY: Why? How do we know he didn't invent the thing?
The crew members of Enterprise are totally blasé about time-travel paradoxes. Maybe they think that these humans are so primitive that it won't matter either way? Well, that's just rude.
Quote #8
AGENT 1: What do you think?
AGENT 2: He's a Russki.
The FBI agents who interrogate Chekov allow paranoia to drive their analysis. Talk about being primitive…
Quote #9
MCCOY: What's the matter with you?
PATIENT: Kidney dialysis.
MCCOY: Dialysis? My god, what is this, the Dark Ages?
McCoy's reactions to modern medicine are everything. He reacts the same way we would if we saw a medieval barber slapping leeches on some poor soul—with utter shock and horror.
Quote #10
MCCOY: My God, man, drilling holes in his head's not the answer. [...] Now put away your butcher knives and let me save this patient before it's too late.
As usual, "Bones" McCoy pulls no punches. He knows that he could slap some futuristic technology on Chekov's noggin and fix him up in a jiffy, but this savage thinks he knows what's what. These people aren't just rude and uncivilized—they're also arrogant. That's a nasty combo.