Invention concerns finding something to say (its name derives from the Latin invenire, "to find."). Certain common categories of thought became conventional to use in order to brainstorm for material. These common places (places = topoi in Greek) are called the "topics of invention." They include, for example, cause and effect, comparison, and various relationships.

Invention is tied to the rhetorical appeal of logos, being oriented to what an author would say rather than how this might be said. Invention describes the argumentative, persusive core of rhetoric. Aristotle, in fact, defines rhetoric primarily as invention, "discovering the best available means of persuasion." An important procedure that formed part of this finding process was stasis.

http://rhetoric.byu.edu/

invention

  Use Invention in a sentence

in·ven·tion

 

 

1.  the act of inventing.

 

2.  U.S. Patent Law. a new, useful process, machine, improvement, etc., that did not exist previously and that is recognized as the product of some unique intuition or genius, as distinguished from ordinary mechanical skill or craftsmanship.

 

3.  anything invented or devised.

 

4.  the power or faculty of inventing, devising, or originating.

 

5.  an act or instance of creating or producing by exercise of the imagination, especially in art, music, etc.

 

http://dictionary.reference.com/browse/invention?s=t