18.20 The self (Atman), which is of the form of knowledge, is alike and uniform, though distinct, in all beings, even though they may externally, and from the point of view of duty, be distinguished as Brahmanas, Ksatriyas, householders, celibates, fair, tall etc. The immutable selves in all these perishing forms or bodies are unaffected by the fruits of actions. Such knowledge of the immutability of the self in all changing beings, is Sattvika.