In the Bhagavad Gita, there is no long discussion, nothing elaborate. The main reason for this is that everything stated in the Gita is meant to be tested in the life of every man; it is intended to be verified in practice. ↗
Every man needs slaves like he needs clean air. To rule is to breathe, is it not? And even the most disenfranchised get to breathe. The lowest on the social scale have their spouses or their children. ↗
We don't often look into these unpleasant details of our great struggle. We all prefer to think that every man who wore the blue or gray was a Philip Sidney at heart. ↗