Scott Postma

A blog about the Great Books, the Craft of Writing, and Human Flourishing.

Saturday School: Lesson #9 – Supporting your Thesis, Part V (Invention)


Lesson #9 – Supporting your Thesis, Part V (Invention)

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  • Complete the writing exercise
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In the last couple of lessons, we have learned that a deductive argument uses syllogistic logic to make a point that supports your thesis, and an inductive argument offers particular examples that either support your thesis directly, or that support your thesis indirectly by supporting your deductive argument.

Today’s Lesson

Today’s lesson is the cure-all for what some call writer’s block, and it’s called topics of invention.

Topic comes from the root word topos or topoi meaning location or categories. Invention means to devise matter, in particular, true or plausible matter that is compelling in the support of your thesis.

Literally, we could say that “topics of invention” are “places to find things.”

In antiquity, these were divided into categories of “common” and “special” topics of invention. Common, referred to more general ideas, and special referred to the three divisions of oratory: political, forensic, and ceremonial (It’s not important to know these at this point, but just to be familiar with the terms.)

There are seven common topics of invention that writers should be familiar with: definition, comparison, division, relationship, circumstance, notation and testimony.

We will form questions for five of the topics of invention that are most useful in developing arguments for our thesis:

  1. What is the definition of X? What are its characteristics, both general and specific.
  2. What is the difference between X and Y? How are they different, and how are they alike, and to what degree?
  3. What is the relationship between X and Y? cause and effect? antecedent and consequence? contraries or contradictions?
  4. What are the circumstances of X? Is it impossible; is it improbable; is it probable; is it certain?
  5. Is there any credible testimony that supports my argument? Is there an authority, a statistic, a law, a maxim, a precedent, or an example?

Writing Exercise

Use each question above to invent five new arguments for your thesis.

Do you want to touch readers with your words, learn the craft of writing, or simply improve your writing skills from a classical perspective? Join me each week for Saturday (Writing) School. Every Saturday I’ll send a lesson to your inbox you can complete in an hour, or you can work on it at your leisure. It’s free!


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About Scott Postma

Scott is a writer and teacher living in North Idaho. He loves teaching the Great Books, writing and blogging, and collecting more books than he'll ever read in a lifetime. You can subscribe to the tribe and follow him on Twitter, Facebook, and Google Plus.

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