I was running with my daughter's goldendoodle, Addie, when her tongue lolled to one side and she started to lag. Naturally, I got to thinking about a fundamental precept of classical argumentation.

As Aristotle advises, if you want to persuade your audience, make a mixed rhetorical appeal.

What he meant was appeal to the whole person (or in this case, the whole creature) — not just to the head (logos), the heart (pathos) or the soul (ethos), but to all three.

So I decided to give it a try.

First I tried logic. Logical appeals come in two varieties: inductive and deductive.

Inductive reasoning involves presenting a series of facts or observations until the weight of accumulated evidence results in a leap to the desired conclusion.

Deductive reasoning is based on the more structured three-step syllogism: If a major premise is true ("All men are bald"), and a minor premise is true ("Socrates was a man"), then the conclusion is true ("Socrates was bald").

I began with inductive reasoning.

I pointed out the faster we ran, the sooner we would be finished. No good. Then I observed that in dog years she was half my age. Nothing. Finally, stretching the truth a bit, I told her we were nearly home. Nada.

Next I tried deductive reasoning.

"All right, Addie," I said. "Listen up. Four-leggeds run faster than two-leggeds. You have four legs, and I have two. Therefore, you can run faster than I."

Despite the sophistication of my logical appeal, my argument failed to produce the desired result. Addie opened her mouth and panted, but her speed did not increase.

So I appealed to her feelings and emotions.

"Let's go home and see Markus," I said. She loves Markus and is always excited to see him. Her pace quickened. The only problem was that Markus was not at home. Markus was still at work.

Having compromised my integrity, I went a step further.

"Markus will give you a treat when we get home," I said shamelessly. Her pace quickened to the point I had to pick up mine.

Although I had achieved my goal, I was curious to see if she would respond to ethos, so I ventured an ethical appeal: "Because you're a good dog, you deserve a reward."

No change. Hmmm, I thought, maybe the appeal was right, but the wording was wrong. "Because you're a good dog," I said, "you deserve a treat."

This time she lurched forward. But if she had responded to the word "treat," her response was to feelings (hunger and desire being among the most basic), not ethics.

Which left me with an unsettling conclusion.

Dogs have a simple worldview. They understand feelings. They have basic desires, and they see it as our job to fulfill them.

Humans, on the other hand, are more sophisticated. They're capable of mounting and responding to a variety of rhetorical appeals. Unfortunately, they're also prone to misrepresent the truth in order to achieve their goals.

Stephen Wilbers offers training seminars in effective business writing. E-mail him at wilbe004@umn.edu. His website is www.wilbers.com.