It’s old. It’s Greek. And, unsurprisingly, it involves geometry. But let’s save the history lesson for the appendix and jump right in.

Fundamentally, there are three ways to persuade someone. These are called modes of persuasion or rhetorical appeals. Any one of them can work, but when you can get more than one of these appeals working together, your effectiveness will multiply.

ONE – Credibility (Ethos)

When a doctor tells you to do something for your health you are more likely to believe her than your brother-in-law. But, in our over-credentialized age, this appeal is not as simple as having the right initials behind your name. We are more likely to be persuaded by those who model what we value or want to be. For example, how much credibility would you give a personal trainer who is obviously out of shape?

TWO – Logic (Logos)

People can be persuaded by logic. If I show you data that links smoking and lung cancer, then I don’t have to be a doctor to be persuasive. Theoretically, logic is the purest and best of all appeals. But if you’ve had any experience with non-theoretical people, you know that logic doesn’t always apply. Smoking is the perfect example. Smokers don’t disagree with the logic that smoking is bad for you. So, if you want to persuade someone to stop smoking, you need more than logic.

THREE — Emotion (Pathos)

Emotion is messy, unpredictable, and oh so powerful. Some have described being overcome with emotion as something that happens to a person against their will, depriving them of agency — quite literally an assault. While there are hundreds of words to describe the many shades of emotions we can feel, when it comes to persuasion, I think that only five are elemental.

  1. Love – We are all connected, the world is full of beauty and wonder. Kitten pictures.
  2. Pity – Isn’t it awful what happened to this poor person?
  3. Fear – Something like this could happen to me!
  4. Anger – This is wrong!
  5. Greed — the possibility of gain.

For example, while you might deeply regret something you’ve done, only the fear of regretting something you’ve done or haven’t done is likely to be persuade you.

For business, Fear and Greed are usually the most persuasive. Greed is not a dollar amount, but an emotion. It’s flip side, the fear of loss, is often a more persuasive emotion.

Anger is only really persuasive when directed at people. It is almost impossible for a person to be angry at an institution without transferring that anger onto an individual.

Anger, Fear and Love are the emotions that cause things to go crazy on the internet. When looked at which from an evolutionary standpoint, it makes a lot of sense that “This could get us all killed! I must tell the tribe!” should be deeply wired into our psyches.

But however, you analyze them, emotions are powerful stuff when it comes to persuasion.


When you put all three appeals together you get what I call the persuasive triangle.

Any persuasive message fits on some point in this triangle. And my contention is, the closer you get to the middle, the more powerful your appeal will be. Let’s use an example:

Let’s say I want to convince my 73-year-old father to quit smoking. I could simply say, “Dad, smoking causes lung cancer.” This is all logic. And it’s unlikely to work. Because, he knows it already. And if this message was going to work, it would have worked before now.


So how can we move our appeal closer to the center of our triangle? Credibility is going to be hard to come by because this is my Dad. (I think, on some level, you’re always a little bit of a punk to your Dad.) But this is the same problem advertisers have faced since Don Draper had first his three-martini lunch: Why would I believe anything I read in an ad (or anything a salesman says) when I know that the speaker has skin in the game. They make money when they make a sale. 

One solution to is to borrow credibility. “Four out of Five Dentists recommend Trident to their patients who chew gum.”  And it’s crazy to me that line works at all. When you think about it, it’s not a ringing endorsement. It could easily be taken to mean, “Yeah, if you’re going to chew gum, which I don’t recommend, then chew trident. It’s the best of a bad bunch.”

But that’s not even close to the weirdest thing about credibility appeals. Sometimes an appeal to authority doesn’t have to be even remotely connected to the truth. Think four out of five dentists are right about chewing gum?

One out of one illustrated dentists recommend Viceroys to their patients who smoke!

More doctors smoke Camels. They’re probably fine!?! But you know, maybe they’re not smoking in a professional capacity. Maybe somebody should study this. How about some science?

Well, thank goodness we have “scientific” evidence. And my personal favorite: The health cigar.

Borrowing credibility isn’t always so foolish or evil. But like any tool, it can be misused.

To get my Dad to quit smoking, I could honestly borrow credibility from a lot of sources. The Surgeon General, for instance. But that’s probably not going to work either. For one thing, the Surgeon General’s warning is right on the side of the pack. Everybody knows it already.


So, let’s try to get some emotion into the mix and see if that changes things. And to do that, we need a deeper understanding of our audience of one. If I just think of him as my 73-year-old Father, then there’s not much wiggle room. But if we recognize that he’s also a 73-year-old Grandfather, then some opportunity opens up.

How about, “Quit smoking, so you’ll have more time with your grandkids?”

  • Logic: Smoking is killing you. If you quit you’ll live longer.
  • Emotion: Grandpa taking grandkids to get Ice Cream in a Norman Rockwell painting.

Or, “Quit smoking, because if the grandkids see you smoking, they will be more likely to start.”

  • Logic: Smoking is bad for you. Your grandkids look up to you.
  • Emotion: Suffering, grey-skinned, cancer-riddled grandchildren.


Be it an ad, a management conversation or an appeal to a loved one, the more you can successfully consider and combine multiple modes of persuasion, the more successful you will be.

Why should you get your car regularly serviced?

  • Logic: To protect the value of your car.
  • Credibility: AAA and consumer reports recommends an oil change every three months or 5,000 miles.
  • Emotion: Your car needs to be a safe way to transport your kids.

Appendix – Aristotle and the Modes of Persuasion

Beyond a certain point in history it becomes impossible to track the provenance of an idea — people simply didn’t write things down — so, I think it’s safe to say that all of the ideas here were first codified by Aristotle in his Rhetoric. It is an immensely practical and useful work, even if it sometimes suffers in translation, or from the people who teach it.

If this is the first time you are encountering the idea of the modes of persuasion, I think somebody in your education owes you an apology and a refund. Persuasion and persuasive communications is such an important part of everyone’s life and work, you make people more capable and powerful by teaching them how to use these tools.