Rhetoric and Dialectic: The Difference and Why It Matters

I’ve been a public speaking teacher for five years and I’ve found that one of the most important tools in the mental arsenal of readers, writers, and public speakers is the rhetoric/dialectic distinction of Aristotle. Rhetoric and dialectic are distinct forms and even methods of communication, and as such should be distinguished. Here is a summary definition of each:

  1. Dialectic is the art of utilizing logical form well for the discovery and recognition of truth and probabilities.
  2. Rhetoric is the art of discovering what is persuasive, why it is persuasive, and for what it is persuading. It is also the use of persuasion.

Clearly, these two are related. For instance, logic, which is part of dialectic, helps one to be more rhetorically capable in the case of debate. But knowing logic without knowing what actually persuades or interests others can make a speaker or writer boring and unhelpful. This is especially important if Aristotle was correct when he observed that:

Further, in dealing with certain persons, even if we possessed the most accurate scientific knowledge, we should not find it easy to persuade them by the employment of such knowledge. For scientific discourse is concerned with instruction, but in the case of such persons instruction is impossible; our proofs and arguments must rest on generally accepted principles, as we said in the Topics, when speaking of converse with the multitude.

Some people, because they lack logical training or have a short attention span, cannot be convinced of the truth by careful argument. Therefore, instead of careful argumentation, inference from commonly accepted principles must be used. These commonly accepted principles do not strictly have to be true. While I think that Aristotle is right when he says that rhetoric with some basis in truth is more persuasive, the problem is that many who know the truth are not good at putting it rhetorically. The fact of the matter is that in practice, the more vaguely positive something sounds, the persuasive it can be to large crowds because people will fill such terms in with their own meanings. Rhetorical principles typically just have to be emotionally engaging, easily memorized, and easily convertible with reference to their meanings. In American political rhetoric, some of the commonly used and emotionally engaging principles are things like:

  1. Terrorists are scary.
  2. Misogyny is bad.
  3. The wrong side of history is bad.
  4. We are a specific kind of people and that idea is not who we are.
  5. The constitution is good.

On the other hand, the most persuasive argument about mathematics to a room of mathematicians would be an argument of pure logic, clearly defined principles, and detailed enumeration of the steps utilized to discover a conclusion.

A man skilled in rhetoric would know the difference between an audience of bored college students and a room of mathematical experts.

Dialectic and Rhetoric in Speech and Writing

Using dialectic is for doing research and constructing an argument based on the best evidence available. A sign you are reading dialectic might be an outline of the argument in the text so that people can follow the syllogisms carefully. Of course, a rhetorician knows how to use a syllogism is a way that seems like dialectic but is really just persuasion.

But, if a paper were to be presented to an audience that wasn’t a peer-review board, then one would determine which of types of evidence are likely to be the most convincing to that audience and present accordingly. Typically articles sent for peer-review are meant to advance knowledge and while they can use engaging language, typically should show evidence, state assumptions, explain biases, report counter examples, show a careful argument outline, and provide clearly stated conclusions. Of course, results in the world of peer-review will vary. But nevertheless, the peer-review system provides the illusion of the genre of dialectic.

On the rhetorical level, if you wished to present your scientific findings about exercise to athletes, you wouldn’t necessarily present the evidence that made the conclusion seem most probable. Instead you would explain the results and give specific examples which would make the information seem the most useful for achieving results.

Questions to ask when writing a paper or speech:

  1. Are my premises true?
  2. Did I cite compelling evidence?
  3. Is my argument valid?
  4. Is the argument to complicated to briefly explain to a group?
  5. Am a stating the argument in a way that will be compelling to my audience?
  6. If I am leaving anything unstated or overstating a case for rhetorical verve, am I capable of qualifying and defending the truth in a more fact oriented context?

Dialectic and Rhetoric in Listening and Reading

When reading and listening, the distinction is still important. For instance, you’ll want to know what the author is trying to convince to do, believe, or support. Once you know that you can more easily discover which facts might be intentionally left out and whether or not those facts contradict the key points of the speech or paper. Similarly, you’ll be able determine if the call to action is related to the facts presented.

Knowing whether somebody is using rhetoric to win a crowd or to create distance between the speaker and somebody else is also important. It can keep us from vilifying somebody who is simply “playing the game.” It can also help us to recognize when something is simply stated for rhetorical flourish rather than meant to be accepted as a fact.

In political rhetoric, the blur between persuasion and fact is taken advantage of, often to the detriment of voters.

Questions to ask when listening or reading:

  1. What is the author trying to say?
  2. What is the author/speaker trying to get me to do (buy something, do something, believe something, examine the claims and logic, etc)?
  3. Is the author likely to be accurate?
  4. Are the arguments valid?
  5. Are the facts true?
  6. Are the premises left out of the argument actually true?

The Distinction From Aristotle Himself

Now, as it is the function of Dialectic as a whole, or of one of its parts, to consider every kind of syllogism in a similar manner, it is clear that he who is most capable of examining the matter and forms of a syllogism will be in the highest degree a master of rhetorical argument, if to this he adds a knowledge of the subjects with which enthymemes deal and the differences between them and logical syllogisms. For, in fact, the true and that which resembles it come under the purview of the same faculty, and at the same time men have a sufficient natural capacity for the truth and indeed in most cases attain to it; wherefore one who divines well in regard to the truth will also be able to divine well in regard to probabilities.[1]

 

Nevertheless, Rhetoric is useful, because the true and the just are naturally superior to their opposites, so that, if decisions are improperly made, they must owe their defeat to their own advocates; which is reprehensible. Further, in dealing with certain persons, even if we possessed the most accurate scientific knowledge, we should not find it easy to persuade them by the employment of such knowledge. For scientific discourse is concerned with instruction, but in the case of such persons instruction is impossible; our proofs and arguments must rest on generally accepted principles, as we said in the Topics, when speaking of converse with the multitude. Further, the orator should be able to prove opposites, as in logical arguments; not that we should do both (for one ought not to persuade people to do what is wrong), but that the real state of the case may not escape us, and that we ourselves may be able to counteract false arguments, if another makes an unfair use of them. Rhetoric and Dialectic alone of all the arts prove opposites; for both are equally concerned with them. However, it is not the same with the subject matter, but, generally speaking, that which is true and better is naturally always easier to prove and more likely to persuade. Besides, it would be absurd if it were considered disgraceful not to be able to defend oneself with the help of the body, but not disgraceful as far as speech is concerned, whose use is more characteristic of man than that of the body. If it is argued that one who makes an unfair use of such faculty of speech may do a great deal of harm, this objection applies equally to all good things except virtue, and above all to those things which are most useful, such as strength, health, wealth, generalship; for as these, rightly used, may be of the greatest benefit, so, wrongly used, they may do an equal amount of harm.[2]

References

[1] Aristotle, Aristotle in 23 Volumes, Translated by J. H. Freese., ed. J. H. Freese, vol. 22 (Medford, MA: Harvard University Press; William Heinemann Ltd., 1926), 1355a.

[2] Aristotle, Aristotle in 23 Volumes, Translated by J. H. Freese., ed. J. H. Freese, vol. 22 (Medford, MA: Harvard University Press; William Heinemann Ltd., 1926), 1355a–1355b.