When one subject is expressed in different forms, classify the art by the status and function of its premises.
Demonstrative: Certain premises necessitate a conclusion.
Dialectical: Conceded or commonly accepted claims are used in debate.
Rhetorical: Testimony or probable signs persuade toward a favored judgment.
Poetic: Images and metaphors create attraction or aversion.
In particular, both rhetoric and poetry can be eloquent; the decisive difference concerns the premises and mental operation involved.