The Vedic deity most closely associated with rta is Varuna.
Soon it transcended its passive role as a mere signifier and took on a greater one, that of an active imposition of order. Not only the natural principles, but the gods and goddesses themselves, were obliged to abide by rta. Rta became the father, the law of justice and righteousness, unyielding but eminently fair. It grew, as Radhakrishnan states, from "physical" to "divine" in its purview.
The world's seeming mess of altercating fortune, the caprice of the divinities, was now intelligible. Indeed, there was a single, unchanging harmony working 'behind the scenes.' A right path existed, ready to be taken by the righteous ones. Rta signifies the way life ought to be, shifting from physical to divine, from natural to moral order. Rta was morality, the equitable law of the universe. The conception of this all-transcending, supramental force that is, practically, the same concept as later understandings of dharma, is captured in this early Vedic prayer, preempting the liturgical strains of classical Hindu mantras involving dharma:
Thus we see the logical progression of an early 'course of things' into an all-encompassing moral order, a path and way of righteousness, a universal harmony, in the Vedic idea of Rta.