The Republic by Plato Part 3 Page 97

other memorials of honour, the greatest that we have to give. But him who fails, we must reject. I am inclined to think that this is the sort of way in which our rulers and guardians should be chosen and appointed. I speak generally, and not with any pretension to exactness.

And, speaking generally, I agree with you, he said.

And perhaps the word ‘guardian’ in the fullest sense ought to be applied to this higher class only who preserve us against foreign enemies and maintain peace among our citizens at home, that the one may not have the will, or the others the power, to harm us.

The young men whom we before called guardians may be more properly designated auxiliaries and supporters of the principles of the rulers.