Here's the whole idea in one breath: whenever anyone tries to move you, they're pulling one of three levers — who they are, how you feel, or whether it adds up. Two and a half thousand years ago someone noticed this, named the three levers, and we've been using the same three ever since.
Picture the Place It Was Born
Athens, about 2,400 years ago — a brand-new, noisy kind of city where ordinary blokes had to stand up in the assembly and the law court and argue their own case. No lawyers to hide behind. If you couldn't persuade a crowd, you lost: your argument, your money, sometimes your neck. So persuasion stopped being a knack and became a skill you could be taught, with a name: rhetoric.
A philosopher named Aristotle sat and watched the speakers who actually won, and noticed they all reached for the same three things. He called them the three means of persuasion — and we still use his Greek names today.
The Three Levers, Once
Ethos is the who. “Trust me — I'm a doctor.” It works through the speaker's credibility and character.
Pathos is the heart. “Imagine your little sister breathing this air.” It works by making you feel — fear, hope, pride, pity, anger.
Logos is the head. “Three of four streets flood; therefore we need the drain.” It works through facts, reasons and logic.
Flick the levers in the toy above. One lever alone nudges the crowd. All three together, and the room is yours — which is exactly what the great speeches do, then and now.