Sarvasara Upanishad refers to two concepts: "Mithya" and "Maya". It defines "Mithya" as illusion and calls it one of three kinds of substances, along with Sat (Be-ness, True) and Asat (not-Be-ness, False). "Maya", Sarvasara Upanishad defines as all what is not Atman. Maya has no beginning, but has an end. Maya, declares Sarvasara, is anything that can be studied and subjected to proof and disproof, anything with Guṇas. In the human search for Self-knowledge, Maya is that which obscures, confuses and distracts an individual.