Aristotle may not have been the first troper, but he's the first troper for whom we have evidence, and the evidence is this work, Poetics, the great-grand-daddy of all Books on Trope. (Incidentially, Poetics is not the Greek name but the Latin translation.)
It is based on his analyses of Greek epic poems, such as Homer's works, and of Greek tragedies—a term which, at the time, did not require an unhappy ending; nowadays we tend to call it Drama. note Early on in the text, he even promises an in-depth look at Comedy. Sadly, that section's long been lost—though we do get a few pointers in the text we have, on his basic thoughts on the genre. Full text here.
Poetics is considered the most influential work of criticism ever, introducing ideas like three-act structure of beginning-middle-end as well as the dramatic unities. It defined the purpose of tragedy, the pros and cons of various kinds of plots, all of which actively shaped theatre for several centuries . As a result of the fortunes of history, Poetics had a bigger influence on French and German drama than English theatre (who largely followed the aesthetics of Roman Drama and criticism and as such routinely violated Aristotleian unities). The funny thing about this work is that while Greek tragedies are often studied through the lens of Aristotle's terminology, these tragedies were not really defined by these tropes themselves and indeed contain, as Aristotle himself notes, many Unbuilt Trope. Aristotle was merely describing and analyzing existing drama after the fact.
Tropes first described (to the best of our knowledge) in Aristotle's Poetics
- Acceptable Breaks from Reality: Advocated the notion that a storyteller should put more effort into making their story believable without forcing them to adhere to strict realism if taking a few liberties here and there made for a better story overall.
- Anti-Hero: The best kind of protagonist for a tragedy, to him—he notes that a story featuring a truly "good" hero going through intense hardship would risk inspiring anger in the audience, whereas a Villain Protagonist would risk failing to inspire sympathy.
- Bittersweet Ending: A major fan of this, as ideal for poets who don't want to try for big reveals every darn time.
- Catharsis Factor: Indeed, the work that defined catharsis in its modern meaning.
- Contrived Coincidence: He denounces "an unconvincing possibility" and prefered overtly impossible but convincing events.
- Deus ex Machina: Hated it—in fact, condemns Euripides's Medea for putting the hero into a situation where this is the only means of getaway.
- Doing In the Wizard: Aristotle didn't approve; he preferred the aesthetically convincing to the merely possible.
- Downer Ending: These endings he considered middle of the road — better than some happy endings, worse than others.
- Emotional Torque: He was one of the first people to recognize and discuss the utility of provoking strong emotions of all sorts, not just happiness and joy.
- Fatal Flaw: According to Aristotle, seeing a prosperous person fall is a good source of pathos, and that it's more pathetic to see a not-entirely-bad person suffer due to a fatal mistake than to see wholly good people suffer for reasons beyond their control.
- Greek Chorus: Of course, he just referred to it as the chorus. He advised using it as little as possible, because the story-teller should be telling a story, not giving commentary on it, unless, and only to the extent that, the commentary helps move the story.
- Happy Ending: Aristotle thought that the best plot for a tragedy was one in which The Reveal caused the hero to realize the harm of what he was about to do, and therefore not do it. On the other hand, he thought the worst was one where the character decided not to do an evil deed without The Reveal giving him a motive to do so.
- Random Events Plot: Did not approve.
- Reality Is Unrealistic: Aristotle's opinion was that a story should prioritize being plausible to the audience over being actually realistic.
- The Reveal: Famously delves into the inner workings of the trope.
- Rule of Cool: His explanation for why The Odyssey works despite its at times absurd plot points: Homer was just that good at making you not care, because it's awesome.
- Special Effects Failure: Warned that scenes that sound awesome in epic poetry can look ridiculous when performed on a stage.
- Spectacle: Aristotle didn't approve much of making this a high priority; he held that spectacle should only help a story powerful in itself—the story shouldn't rely on it.
- Three-Act Structure: Often cited as the earliest work to define it.
- Tragic Hero: He defined this trope extensively in his work. To Aristotle, a tragic hero was an active figure who was largely sympathetic, noble in character and standing to whom adversity falls as a result of a Tragic Flaw. For Aristotle, the tragic heroes were ideally Kings and Soldiers and modernist drama disagrees with Aristotle on this point. Arthur Miller wrote that the common man could also be a tragic figure.
- Twist Ending: The ideal ending = Reversal + Recognition.
- Unsympathetic Comedy Protagonist: He notes that comedies tend to portray people as worse than they are.
- Wacky Wayside Tribe: Defied; any part of the story that cannot be logically connected to the main action should be avoided.
- Willing Suspension of Disbelief: Notes that epics have a greater threshold for this than tragedy, for various reasons.