What is a poem that expresses its theme as an aphorism called?

A poem that expresses its theme as an aphorism is called a gnomic poem. A gnomic poem is a short, wise saying that expresses a general truth or moral principle. Gnomic poems are often found in collections of proverbs and maxims, and they are often used to teach moral lessons. Some famous examples of gnomic poems include the following:

* "The greatest wealth is to live content with little." (Plato)

* "A friend in need is a friend indeed." (Proverb)

* "The only true wisdom is in knowing you know nothing." (Socrates)

Gnomic poems are often written in a simple and direct style, and they often use figurative language to make their point. They can be a powerful way to communicate a moral message or to teach a life lesson.