Star Trek are basically Greek-style morality plays. They could as well be e.g. Aesop-style fables in most instances. And they adopt traditions of Greek theatre of clearly signposting the characters through appearance without worrying the least bit about hitting the viewer over the head with it.
Less so in the newer series, but TOS, TNG, Voyager and DS9 very much follows a structure of setting a scene, introducing a conflict that at it's core is usually based around a simple dilemma of morality or ethics, and having a part of the resolution be a dialogue that explicitly addresses the dilemma.
Less so in the newer series, but TOS, TNG, Voyager and DS9 very much follows a structure of setting a scene, introducing a conflict that at it's core is usually based around a simple dilemma of morality or ethics, and having a part of the resolution be a dialogue that explicitly addresses the dilemma.