Dharma is perhaps the most important term in the culture and spiritual philosophy of India but also perhaps the most difficult to understand. It is roughly understood as ‘duty’, the ‘law that upholds’ or the ‘law of life’. This explanation by Swami Krishnananda (Divine Life Society) illuminates its real meaning.
“
The law that operates outside is the law of the cosmos. There are no two laws – God’s law and man’s law; universal law and individual law. No such thing is there. Such thing as ‘my law’ or ‘your law’ does not exist. There is only one law operating everywhere, in all creation, visible or invisible, in all realms of being. The same law is there for the celestials, the humans and the subhuman creatures. Everyone is controlled by a single principle of ordinance. That is called Dharma.
It operates as gravitation in the physical level; it operates as love in the psychological level; it operates as chemicals in the chemical level and it operates as integration of thought in our mental level, the level of cognition and thinking. It ultimately operates as the connecting link between the subject and the object, on account of which there is knowledge of anything at all. That is called Dharma.
Dharma is an integrating force of anything that is even apparently in disparity. Anything that is disconnected, apparently isolated, not visibly connected, is actually connected, and that connecting principle is called Dharma. And Dharma becomes an integrating principle because of the presence of the ātman that is behind it. There is no such thing as Dharma independent of the operation of the ātman. What you call Dharma or law is the ātman working. Its own law is its Being; its Being is its law; they are not two different things.
– From the commentary on ‘The Brihadaranyaka Upanishad’ by Swami Krishnananda, The Divine Life Society. See more: https://www.swami-krishnananda.org/brdup/brhad_II-05.html