Science fiction tends to reflect the times in which it was written; since science fiction is the exploration of the human condition in the face of advances in science and since the technological bogeyman that is foremost in everyone's minds changes from era to era, this is not surprising.
However, science fiction is still fiction and like all fiction, it will reflect the mores that were current in the era in which it was written.
A case in point is The Enemy Within.
In my discussion of The Naked Time, I mentioned that Kirk, while suffering from an affliction that brought deep-seated emotions and desires to the surface, revealed his frustrated desire for Yeoman Janice Rand. In The Enemy Within, this desire explodes to the surface in the form of Kirk's evil half, which is separated from his good half by a transporter malfunction.
Being evil, Kirk's evil half raids Dr.McCoy's liquor cabinet, swaggers through the Enterprise's corridors while drinking Saurian brandy straight from the bottle and overacting shamelessly and then winds up in Janice Rand's quarters where he attempts to force himself on her.
Kirk's evil half gets liquored up after helping himself to McCoy's booze stash
Later, Yeoman Rand gives a tearful account of the evil Kirk's assault on her virtue to the good Kirk, Mr. Spock and Dr. McCoy; as an aside, she mentions she had not wanted to say anything about the attack since she had not wanted to get Kirk into any trouble.
Obviously, society's attitude toward sexual assault have changed considerably since the late 60's.
This point is hammered home by Mr.Spock's rather insensitive comment to Yeoman Rand at the episode's conclusion in which he states that she no doubt found that the evil Kirk had some interesting qualities.
His comment (delivered with a facial expression that can only be described as a leering smirk) almost makes his earlier statement to Kirk, "If I seem insensitive to what you're going through Captain, understand it's the way I am", seem almost prescient.
As in many of the earlier Star Trek: The Original Series episodes, characters not of the Kirk-Spock-McCoy Triumvirate seem to get quite a bit of screen time. Yeoman Rand plays a key role in this episode. Lieutenant Sulu also figures prominently in this episode. As leader of the landing party that is stranded on Alpha 177 by the transporter malfunction, Mr. Sulu manages to maintain his composure and sense of humor despite temperatures (and the landing party's chances of survival) dropping with each passing second.