Bharata Natayam dance dates back to ancient Vedic rituals from approx. 3000 BC considered to be a Golden Age when art, science, mathematics, astronomy, architecture and religion were not separate fields, but were oriented to one Universal cosmos.” Hence, this principle. Golden (age) + rule = Golden Rule, a universal truth of dance and drama technical procedure*. So titled by Mimi Janislawski (among other America dance instructors) because it is THE basic expression of technique, emotional and spiritual procedure for a dancer and/or actor/actress.
As explained to me by Mimi, the technical comes out of you (as the vehicle of movement) and becomes the emotional quality (bhava) as it goes out from you. It becomes the spiritual/ethereal quality (rasa) as it received. The rasa is the exchange between artist and audience, and/or, for example when practicing alone, between artist and the Universe. It is what draws the beholder into the dance so it becomes full circle ~ the beholder participating through the dancer.
*The Golden Rule is the first poetic meter of the the Nāṭya Śāstra the ancient Hindu treatise on the arts, which has influenced dance, music and literary traditions in India. It is attributed to the sage Bharata Muni for its authorship ~ the one who got ‘a round tuit’ and compiled about 6000 verses structured into 36 chapters. It describes the theory of Tāṇḍava dance (Shiva), the theory of rasa, of bhāva, expression, gestures, acting techniques, basic steps, standing postures—all of which are part of Indian classical dances. Dance and performance arts, states this ancient text, are a form of expression of spiritual ideas, virtues and the essence of scriptures. Read more: The Mirror of Gesture (1917) Harvard University Press.