The Republic by Plato Part 1 Page 47

Indeed, Thrasymachus, and do I really appear to you to argue like an informer?

Certainly, he replied.

And do you suppose that I ask these questions with any design of injuring you in the argument?

Nay, he replied, ‘suppose’ is not the word — I know it; but you will be found out, and by sheer force of argument you will never prevail.

I shall not make the attempt, my dear man; but to avoid any misunderstanding occurring between us in future, let me ask, in what sense do you speak of a ruler or stronger whose interest, as you were saying, he being the superior, it is just that the inferior should execute — is he a ruler in the popular or in the strict sense of the term?