A rhetorical device is a technique for making language persuasive. It is not an error — but several of them become fallacies the moment they replace the reasoning instead of carrying it.
Devices that work by saying something more than once — the oldest way to make a phrase stick, and the easiest to overdo.
Devices that arrange clauses so the shape of the sentence carries part of the argument.
Devices that change who is being spoken to, or stage a conversation with the audience.
The classical grounds of persuasion — character, emotion, reasoning and timing.
Devices that say something while appearing not to, or soften what would otherwise land hard.
Devices that work by overstating or understating the case on purpose.
Rhetorical devices are the oldest tools in persuasion, and unlike the fallacies and biases catalogued elsewhere on this site, there is nothing wrong with them. A tricolon is not a mistake. Anaphora is not a trick. They are what makes a sentence memorable instead of merely correct.
The line matters, though, and it is thinner than it looks. A rhetorical question is a device until it contains an assumption the audience never agreed to, at which point it is a loaded question. An antithesis is a device until the two halves are offered as the only options, at which point it is a false dilemma.
Every entry here says where its own line sits, because the useful skill is not avoiding these techniques — it is noticing the moment one of them has started doing the arguing.
See also the logical fallacies these devices can become, and the cognitive biases that shape judgement before any of it is written.
