Universal soul is one of the main Keystone of the philosophy and the thought of the Upanishad. Brahma satyam Jagat Mitya Jeevo Bramanah Parah talks about the impermenance of the body and its existence.
Sabha or Mahasabha during the Chola empie referred to the exclusive assembly of Brahmans/gatherings of the adult male members in the agraharas, that is, the rent free brahmadeya villages. These assemblies enjoyed a large measure of autonomy.