Looking at the teaming oceans, the unnumbered blades of grass in the fields, the myriad stars in the night skies, the universe is abundant beyond measure, it doesn’t jealously count each blessing it dispenses. But abundance without purpose or a plan, becomes profligate, reckless and ineffective. So there is a governing factor that comes into play: karma, curbing excess, judiciously regulating the system, and insuring overall integrity to it.
The Nodes are representations of an energy of a spiritual/karmic sort. In Hindu astrology the Nodes are Rahu and Ketu, asuras, or “spirits/demons” that are uncontrollable and dangerous, much like the spiritual kundalini fire resident in each of us.