Most things we want in business, and in life, depend on other people. That means we have to persuade them. That means we have to make arguments.

Argument is the most fundamental tool of persuasion that exists. But it's also what makes a group smarter than the people in it.

"If you're in business you are persuading people whether you know it or not."

Dale Williams, strategy coach, Cape Town

Or, you should be. Most of what passes for argument is merely assertion.

---

Most disagreements at work follow the form of: The plan won't work. Yes it will. No it won't. Neither side justifies why their claim is likely to be true nor refutes the opposing claim. Everyone keeps the same ideas they entered with. An argument, unlike an assertion, requires analysis: why the claim holds, and why it matters.

But in some teams, the problem is even worse: they don't disagree at all. What's the number one rule of brainstorming in a team? That you don't criticise other people's ideas. Except that when psychologists tested it, the groups told to debate generated more ideas than the groups told not to criticise.1

A tech company would never ship code without review. But most teams ship decisions that way.

Rhetoric, which is the art of persuasion, has been practised for more than two thousand years. In the ancient world it was the centrepiece of an educated person's training. Its heir is competitive debate: a sport built entirely around the making of arguments, where classical principles have been applied and refined for decades.

Companies like McKinsey know how essential these skills are, which is why they recruit directly from debating competitions. But most organisations don't. And so that training stays where it is: siloed within dusty tutorial rooms.

I spent thirteen years in that world. What I teach now is the part of it that works in a boardroom: how to build an argument that holds, how to take one apart without making an enemy, and how to work out which disagreements are worth having.