If they had a single master as our troops have, their obedience to him might make them courageous beyond their own desire, or they might be pushed onward by the whip against an enemy which far outnumbered them. But left to their own free choice, they will surely act differently. For my part, I believe that if the Greeks had to contend with the Persians only, and the numbers were equal on both sides, the Greeks would still find it hard to stand their ground. We too have men among us as tough as those you described -- not many perhaps, but enough. For instance, some of my bodyguard would willing engage singly with three Greeks. But this you did not know; and so you talked foolishly."
Demaratus answered him- "I knew, O king, that if I told you the truth, I would displease you. But since you wanted the truth, I am telling you what the Spartans will do. I am not speaking out of any love that I have for Sparta -- you know better than anyone how I feel about those who robbed me of my rank, of my ancestral honours, and made me a homeless exile.... Look, I am no match for ten men or even two, and given the choice, I would rather not fight at all. But if necessary, I would rather go against those who boast that they are a match for any three Greeks."
"The same goes for the Spartans. One-against-one, they are as good as anyone in the world. But when they fight in a body, they are the best of all. For though they are free men, they are not entirely free. They accept Law as their master. And they respect this master more than your subjects respect you. Whatever he commands, they do. And his command never changes: It forbids them to flee in battle, whatever the number of their foes. He requires them to stand firm -- to conquer or die. O king, if I seem to speak foolishly, I am content from this time forward to remain silent. I only spoke now because you commanded me to. I do hope that everything turns out according to your wishes."
This was the answer of Demaratus, and Xerxes was not angry with him at all, but only laughed, and sent him away with words of kindness.