The Bhagavad-Gita (Chapter 3, Verses 18-21) says:
A self-realized man has no purpose to fulfill in the discharge of his duties prescribed by the Vedas, nor has he any reason not to perform such work. Nor has he any need to depend on any other living being.
Therefore, without being attached to the fruits of activities, one should act as a matter of duty; for by working without attachment, one attains the Supreme.
Even kings like Janaka and others attained the perfectional stage by performance of prescribed duties. Therefore, just for the sake of educating the people in general, you should perform your work.
Whatever action is performed by a great man, common men follow in his footsteps. And whatever standards he sets by exemplary acts, all the world pursues.
As we see, the determining factor in people’s upbringing was the example given by the leaders of society. Society can never be virtuous, if its leaders are not. Therefore, the Aryan society paid a great attention to the purity of religious figures and state leaders. The higher caste which a person belonged to was, the stricter requirements were applied to him/her in terms of qualities of this person. The least significant requirements were applied to commoners.
As said above, the external regulating principle of the Aryans’ behavior was their honor. This factor played a great role in the Aryan society. When Arjuna refused to fight, Krishna told him (the Bhagavad-Gita, Chapter 2, Verses 31-36):
Considering your specific duty as a kshatriya, you should know that there is no better engagement for you than fighting on religious principles; and so there is no need for hesitation.
O Pārtha, happy are the kshatriyas to whom such fighting opportunities come unsought, opening for them the doors of the heavenly planets.
If, however, you do not perform your duty of good fighting, then you will certainly incur sins for neglecting your duties and thus lose your reputation as a fighter.
People will always speak of your infamy, and for a respectable person, dishonor is worse than death.
The great generals who have highly esteemed your name and fame will think that you have left the battlefield out of fear only, and thus they will consider you insignificant.
Your enemies will describe you in many unkind words and scorn your ability. What could be more painful for you?