Informative to Persuasive: Ethos


Making the Mind Jump

Ideas are the most valuable things we have but those ideas are worth nothing if they don’t make the leap from your mind to someone else’s mind.

It’s not only a matter of launching your ideas out into the world. They need to be packaged in a way that makes them memorable.

This post is derived from a persuasion workshop I ran in person at a public speaking group in my home town of Christchurch in New Zealand. It includes exercises you can do to make your speaking or writing more persuasive.

What Doesn’t Work

I was trained as a scientist – I have a physics degree – and I work as a software developer. My natural inclination is to regard facts and logic as the only things that matter.

I’ve also dabbled in politics. Years ago, I stood for Parliament for a tiny party you’ve never heard of. I went to meet-the-candidates meetings and did interviews and argued my points rationally. It had no discernible impact.

For many years I’ve been involved in Toastmasters and have given speeches on all sorts of things. My favourite presentation style is the informative speech – taking a complex or technical topic and presenting it for a general audience. Making things simple is good as far as it goes but simple doesn’t always mean interesting.


No doubt many of you have been in similar situations. You’ve had something important to say, you’ve had all your facts together, but … it’s flopped. It’s disheartening. What can we do about it?

From the Other Side

Think about it from the audience’s point of view. When was the last time you changed you mind? I mean, really. We like to think that we’re open-minded but we don’t often change our mind. When we do it’s often not because of new facts.

In school we’re taught debating, with it’s point scoring and rebuttals. We’re taught to write essays with a set logical structure. We’re taught that arguments made of premises and conclusions are the way to persuade someone that something is true.

» Exercise

You can play along at home. Think of a topic that you’d like to tell me about. Think of a fact or an opinion that you’d like to convince me of. Write it down:

What do you want me to know or believe?

And then put down some supporting arguments.

What facts or data do you have to support your conclusions?

If you were going into a debate or writing a high-school essay, you could probably stop there. Let’s be honest: it would probably be dull and unconvincing.

Why We Resist New Information

We have a mental immune system that protects our minds from new information. When new information does get past, we try and fit it to the beliefs we already have.

We’ve had this mental immune system for hundreds of thousands of years, ever since we lived in tribes on the savanna. In those days, the tribe – possibly the only thirty to a hundred people you’d meet in your life – was everything. You lived with them, you ate with them, you slept with them. Changing your mind risked making you the odd one out. And if you were out, you were out. You’d have no shelter, no food, and no mate. For your survival, being right was less important that being part of the group.

When you have Christmas dinner with your family and someone says something you disagree with, do you correct them? Chances are you just keep quiet. Harmony beats truth.

Standing out from the group is scary. If you stand out from the group, your stone age brain reminds you, you might freeze, you might starve, you might be shunned by potential mates and die childless.


It’s no wonder that persuasion is hard. If we’re going to be persuaded, we need to be confident that these catastrophes won’t happen.

The Art of Persuasion

If logic by itself isn’t enough, what does work? To find out, we go to Aristotle. Rhetoric is the art of persuasion and Aristotle literally wrote the book on it.

In Rhetoric, Aristotle described three main modes of persuasion: logos (reasoning, words, and logic), ethos (the speaker’s credibility), and pathos (the emotions and psychology of the audience).



To get past the paleolithic mental defences you need to demonstrate to your audience that listening to you won’t turn them into pariahs. If the person you’re trying to persuade isn’t going to get kicked out of the tribe and die a cold, hungry virgin, they need to trust you and believe that you’re credible.

Do you have the skills and knowledge to talk on this subject? Do you have something in common with the audience? Do you have the audience’s best interests at heart?

At the start of this post I mentioned that the post is derived from a workshop I’ve run at a speakers’ group. It was presented as a simple statement of fact, but its real purpose was to provide a dose of credibility.

The need for ethos is why celebrity endorsements work. I have my mortgage with Westpac and I’m happy with that decision knowing that someone as professional, sincere, and humble as former All Blacks captain Richie McCaw does too. I know that I won’t get kicked out of the tribe for associating myself with such a widely respected local hero.


If you’re presenting, the person introducing you should build up some credibility in the eyes of the audience, but sometimes you need to be your own celebrity endorsement.

In You Talkin’ To Me, his guide to rhetoric, Sam Leith shows how public figures from popular American singers to notorious German chancellors use ethos to claim that they’re just like us.

Don’t be fooled by the rocks that I got
I’m still I’m still Jenny from the block.

Seventy years earlier, at the Siemens Dynamo Works:

German compatriots, my German workers, if today I am speaking to you and to millions of other German workers, I have a greater right to be doing this than anybody else. Once I stood amongst you. For four and a half years of war, I was in your midst. And through diligence, learning – and, I have to say, hunger – I slowly worked my way up. Deep inside me, I always remained what I had been before.

I’m still – I’m still Adolf from the block.

Politicians of all stripes are desperate to show off just how working class, or middle class, or just plain normal they are.

One of New Zealand’s most popular recent Prime Ministers, John Key, had no obvious political convictions, but most of the country agreed that he was the sort of bloke you could have a beer with. He was Prime Minister for eight years.

» Exercise

Look back at the two questions you answered earlier: what do you want me to believe and what supporting arguments do you have?

Now think about how you can get on side with your audience. Why should I believe you? What skills and experience do you have? Can you convince me that you and I have common interests?

Who are you? Why should I like, trust, and believe you?

As well as the logical structure of your message, you now also have credibility – a reason for me to listen to your message.


But Wait, There’s More

Unfortunately, showing that you’re credible and that you have the audience’s best interests at heart still isn’t enough. Even then, facts aren’t that persuasive. We often decide what to believe first and then add the facts on later.

That’s where Aristotle’s third mode of persuasion, pathos, the emotional appeal of your message, comes in. I’ll talk about that in my next post on the topic.

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