Common Topics
    Genus / Species
    Whole / Parts
    Subject / Adjuncts
    Similarity / Difference
    Cause / Effect
    Antecedent / Consequence
    Possible / Impossible
    Past Fact / Future Fact
    Maxims or Proverbs
    The supernatural
Notation and Conjugates

If he knows the topoi [regions, places, lines of argument]--and a skilled speaker will know them--he will know where to find what he wants for a specific case.  The general topics, or commonplaces, are regions containing arguments that are common to all branches of knowledge. . . . But there are also special topics [regions, places, loci] in which one looks for arguments appertaining to particular branches of knowledge, special sciences, such as ethics or politics.
                                                  (Aristotle's Rhetoric)

What to Write?: Using Aristotle's
"Topics of Invention" as a Heuristic

by Tina Blue
August 28, 2007

In his treatise on rhetoric, Aristotle describes strategies of argumentation and analysis that he called the topoi, or the "topics of invention." In Latin these topics were called loci communes (common locations), and we still reference that sense in our term "commonplace." The word "topic" comes from the Greek word for "place," and the topics of invention represent a set of metaphorical "places" where writers can "go" to develop ("invent") material to support their case. 

These rhetorical "commonplaces" are basic categories of relationships among ideas; each "topic" might serve as a place to begin invention--a location for beginning brainstorming and analysis, for discovering things to say about a subject.

In other words, these topics of invention can act as prompts to aid in the process of discovery, the stage in writing that provides the raw material that will become the content of an essay or other piece of writing. These prompts can help a writer to analyze and develop the material for any writing project.

Aristotle divided the topoi into the "Common" and "Special" topics of invention, the former being more general, the latter relevant to each of the three branches of oratory recognized during his time: judicial, deliberative, and ceremonial.

Special Topics
    justice (right)
    injustice (wrong)
    the good
    the unworthy
    the advantageous
    the disadvantageous
    virtue (the noble)
    vice (the base)

For your convenience, here are some updated versions of many of his most useful topics, presented as questions:

·          What happened?
·          Where did it happen?
·          Why did it happen?
·          When did it happen?
·          What does it look like?
·          What are its characteristics or qualities?
·          What are some typical cases or examples of it?
·          How did it happen?
·          What makes it work?
·          How is it made?
·          What caused it?
·          What are its effects?
·          How is it related to something else?
·          How is it like other things?
·          What are its parts?
·          How can its parts be separated or grouped?
·          Do its parts fit into a logical order?
·          Into what categories can its parts or types be arranged?
·          On what basis can it be categorized?
·          How does it resemble other members of its own class?
·          How does it differ from other members of its own class?
·          How much can it be changed and still remain within its class?

Most of you are probably familiar with the five journalist's questions:
Who? What? When? Where? Why?
These questions are actually just simplified versions of the Aristotelian topics.

Not all topics will apply to every writing project, and you may need to apply the topics more than once to your subject. For example, causes and effects are often complex rather than simple, especially in the sort of subject matter you will be dealing with in college-level or professional writing. They may even involve an interlocking nexus of causes and effects. Also, any subject may be composed of a number of subpoints, each of which might profitably be subjected to such analytical questions.

For many writers, a blank page or a blank computer screen seems like an insurmountable obstacle. The Aristotelian topics--or the modernized questions developed from them--can serve as helpful prompts that not only get you started writing, but also help you discover genuinely useful points to make about your subject.