Tag Archives: enthymeme

Reasoning Underlies Organizing and Wording for Persuasive Speeches

As I taught our Speech Class Refresher course last week, I was helping some of our participants with the main points or arguments they wanted to make for their sample persuasive presentation.

The principle that we taught them was parallelism.  That is, that the points or arguments should begin with the same part of speech, such as an action verb.  A bonus to that is alliteration, which means that the points begin with the same sound.  The example I gave was:

  • With a smart phone, you can text.
  • With a smart phone, you can talk.
  • With a smart phone, you can travel.

It hit me this week that organizing and wording points or arguments is the visible cousin to the invisible reasoning that goes behind them.  A speaker must reason his or her arguments before organizing and wording them.  There are two types of reasoning:  inductive and deductive.

Deductive reasoning typically takes two forms.  One Is syllogistic:

  • Republicans control the House of Representatives, which votes on proposed legislation.
  • The President of the United States, who submits legislation for consideration, is a Republican.
  • Therefore, the President should be able to pass legislation he proposes in the House since the majority of voters are from his own party.

The other type is enthymematic.  An enthymeme is deductive, but omits one of the major premises.  It is either an truncated syllogism, or one that simply allows the listener to reach a conclusion through implied, rather than stated reasoning.

AristotleIn his work, Rhetoric, published in 350 B.C.E., Aristotle said, “the enthymeme must consist of few propositions, fewer often than those which make up the normal syllogism. For if any of these propositions is a familiar fact, there is no need even to mention it; the hearer adds it himself.”  He believed that they enthymeme was the strongest form of proof available to a speaker.

So, converting the example above from a syllogism to an enthymeme, we would say:


  • The President of the United States should be able to pass legislation he proposes because the House that votes on it is Republican.

Notice that we omit the premise that the President is a Republican.  It is only implied.

Important as it is, we rarely teach enthymematic reasoning.  I do not cover it at all in public speaking courses.  I have not seen it in a speaking textbook for many years.

Frankly, since reasoning is not visible to audiences, we have simply stopped talking much about it.  Yet, it is one thing to word and arrange arguments.  It is completely another to properly reason a case with them.  Reasoning is first – wording and arranging is second.

In Pursuit of Elegance – What about the Enthymeme?

My book for July, 2009 at the First Friday Book Synopsis is In Pursuit of Elegance: Why the Best Ideas Have Something Missing by Matthew May.

The book covers many areas and numberous examples of the power of the missing element. To quote the author, “The full power of elegance is achieved when the maximum impact is exacted with the minimum input” (p. 6).

I find it surprising that the author does not include a chapter on Elegance in Argument. Some of the most powerful arguments are those that fail to include all of its components, leaving it to the recipient to fill in the blanks.

This type of argument is called an enthymeme. Popularized by Aristotle in ancient Greece, the enthymeme is a syllogism with an implied premise. You are well aware of the famous syllogism: “All men are mortal; Socrates is a man; therefore, Socrates is mortal.”

When the premise is implied rather than provided, the argument becomes an enthymeme. Here are two you likely remember from recent advertising:

“This is your brain. This is your brain on drugs. Any questions?” (The Partnership for a Drug-Free America)

“Want him to be more of a man? Try being more of a woman!” (advertising slogan for Coty perfume)

Therefore, in an enthymeme, the speaker builds an argument with one element removed, leading listeners to fill in the missing piece. Listen to how Paul Waldman in the Washington Post, September, 2003 illustrated this well: “On May 1, speaking from the deck of the USS Abraham Lincoln, President Bush said, ‘The battle of Iraq is one victory in a war on terror that began on September the 11th, 2001, and still goes on. . . . With those attacks, the terrorists and their supporters declared war on the United States. And war is what they got.’ This is classic enthymematic argumentation: We were attacked on Sept. 11, so we went to war against Iraq. The missing piece of the argument–‘Saddam was involved in 9/11’–didn’t have to be said aloud for those listening to assimilate its message.”

In his book, May explains why what is not there often trumps what is. It is unfortunate that he does not extend his case to introduce the enthymeme to his readers.

Remember that one of the most powerful effects of persuasion is when the recipient believes that your idea is his or hers, or when he or she reaches a conclusion that you want, without your own input. The enthymeme is a powerful and elegant tool to do exactly that.

What do you think? Let’s talk about it!