Viveka / Discrimination:

Discrimination is the faculty which distinguishes between the real and the unreal. The whole world outside and the universe that is inside, are unreal. Earth, water, wind, fire, the sky, the ocean, our bodies and the vital force animating them, our minds, our consciousness of ourselves - all are but airy nothingness. The only real thing is the Atman (Self) or Brahman, the Absolute.

~ Sri Swami Sivananda