In this topic you should understand “Subject” and “Object” in very precise way. Dharma is the “Action-Field” while Dharmatma is the “Warrior”. This doctrine called Dharma-Dharmatama Vibhaga addresses the divide between the “Doer” and the “Actions”. To contemplate this teaching, imagine the situation of “Arjun” in the middle of the battlefield. Arjun believed that he was about to do something. And he was reluctant to do so. During this event, Arjun was extremely worried about the guilt of killing his own relatives for the sake of a throne or any other reason.
In his book, Miteiya decodes statements of Krishna in Bhagwat Geeta and presents them in simplistic and comprehendible language. At the end of the dialogue, Krishna proves that Arjun was not the doer but was not even a fragile force.