In rhetoric, a rhetorical device, persuasive device, or stylistic device is a technique that an author or speaker uses to convey to the listener or reader a meaning with the goal of persuading them towards considering a topic from a perspective, using sentences designed to encourage or provoke an emotional display of a given perspective or action. Rhetorical devices can be used to evoke an emotional response in the audience, but that is not their primary purpose.
Logos is the use of logical ideas to appeal to the audience. It's the logical structure of an argument, giving claims, reasons for the claim, and evidence to support the reasons.
Pathos is an appeal to the audience's emotions. Pathos is often used to stir people's emotions to lead them to take an action
Ethos describes the guiding tenets that characterize a community, nation or ideology; it may also appeal to the author's credibility. It is an appeal based on the character of the speaker.
Kairos is an appeal to the timeliness of the argument.
Irony and metaphor
The use of irony in rhetoric is primarily to convey to the audience an incongruity that is often used as a tool of humor in order to deprecate or ridicule an idea or course of action.
The use of metaphor in rhetoric is primarily to convey to the audience a new idea or meaning by linking it to an already familiar idea or meaning. By making the new concept appear to be linked to (or a type of) the old and familiar concept, the person using the metaphor hopes to help the audience understand the new concept.
An example of rhetorical device is this passage attributed to a speech by Abraham Lincoln about a political adversary who had "dived down deeper into the sea of knowledge and come up drier than any other man he knew". This attributed quote uses a body of water as a metaphor for a body of knowledge with the ironical idea of someone who gained so little from his education that he achieved the impossible of jumping into a body of water and climbing back out without getting wet.
Sonic devices depend on sound.
- Alliteration is the use of a stream of words with the same first phoneme, only interrupted by grammatically required words (e.g. a(n), the, to, for, by, etc.). It is used for emphasis, suggesting a humorous or even threatening tone.
- The zoo kept several selfish seals.
- I hate that heartless heathen.
- Assonance is the repetition of a similar set of vowel sounds. It is used to emphasize intensity, mood, and imagery, among others.
- Cacophony is the use of words with unpleasantly rough sounding consonants, usually at the beginning of a word.
- Onomatopoeia is the use of words that attempt to emulate a sound. When used colloquially, it is often accompanied by multiple exclamation marks and in all caps. It is common in comic strips and some cartoons.
- smek – high-fiving someone; smacking someone in the face
- thwap – lying down carelessly; dropping a pile of papers or books carelessly
- kaboom – exploding
- ding-dong – ringing a doorbell
- plop – sitting/lying down carelessly (also a verb: “Plop down on the couch.”)
- bang – exploding; shooting a powerful gun
- pew – shooting a laser gun
Altered signification devices
Devices of altered signification shift the meaning of words.