A work of nonfiction prose that aims at stating and defending a position on some issue is called what?

A work of nonfiction prose that aims at stating and defending a position on some issue is called an argumentative essay, or sometimes simply an argument.

Other terms that are used, sometimes interchangeably with "argumentative essay", include:

* Persuasive essay: This term emphasizes the goal of convincing the reader to agree with the author's position.

* Expository essay: This term highlights the author's goal of explaining their position clearly and thoroughly.

* Critical essay: This term emphasizes the analysis and evaluation of a particular issue or topic, often from a critical perspective.

Ultimately, the specific term used will depend on the specific focus and tone of the piece. However, all of these terms refer to a type of writing that aims to persuade the reader through logical reasoning and evidence.