In the current cycle of creation, Tamōyuga, Prāṇiyuga, and ādiyuga were followed by a period named Maṇijā where the human society reached a new level of evolution. Skills such as agriculture, irrigation, etc were mastered and the society was classified into four divisions: Sādhya, Mahārājika, ābhāsvara and Tuṣita. This was the early origin of the cāturvarṇya system in the upcoming Devayuga.
The sādhyas were men of scientific and spiritual thinking, somewhat similar to the brāhmaṇas of Devayuga. Mahārājikas were rulers and warriors, ābhāsuras (ābhāsvaras) were merchants and skilled workers and Tuṣitas served the other three classes. The sādhyas were masters of Yajña vidyā, which was later propagated during Devayuga by sage Atharvā, son of Brahmā, among the Dēva-trilōkī. The sādhyas however were nirīśvaravādins which is indicated by words such as pūrvē dēvāḥ, suradviṣaḥ, etc. The sādhyas did not accept an omnipresent and omniscient īśvara but instead relied on kṣaṇika vijñāna, perceivable through the sensory faculties. They ascribed the universe and its function to the rules of nature and refused to believe in the existence of a higher power. Due to the utkarṣa of these thinkers, the Maṇijā yuga came to be known as Sādhya yuga.
Sadvāda, Asadvāda, Sadasadvāda, Vyōmavāda, Aparavāda, Rajōvāda, Ambhōvāda, āvaraṇavāda, ahōrātravāda and samśayavāda were the ten siddhAntas (remembered in the Rgveda] prevalent in Maṇijā yuga. A great being named Brahmā arose in thus yuga by the grace of Parā and disproved these daśa vādas to establish Brahmavāda on a firm foundation, propounding the concept of īśvara sattā. The same Brahmā came to be the pravartaka of the glorious Devayuga.
After establishing ēkēśvaravāda, Brahmā classified the earth into dēvatrilōkī and asuratrilōkī. The Himalayan and Pamir regions came to be called svarga ruled by Indra and the residents came to be called Devas. Regions of Africa and present America came to be called asuratrilōkī. The Devas lived in the region spreading across the Himalayan range till the śaryaṇāvata. The residents of dēvatrilōkī were classified as: r̥ṣi, pitr̥, dēvatā, dēvayōni and manuṣya.
The original r̥ṣis were prāṇa tattvas and those who realized these tattvas came to be called by the same name. From mūla prāṇa or r̥ṣi prāṇa, pitr̥ prāṇa or saumya prāṇa originated. The pitr̥lōka was inhabited by those with well-developed pitr̥prāṇa and were ruled by Vaivasvata Yama, son of Svāyambhuva Vivasvān. The saumya prāṇa underwent a two-fold division based on snēha and tēja resulting in the tattvas Bhr̥gu and Aṅgirā. This Yuga, where a Dēva-vyavasthā existed on the earth, came to be called as Devayuga. Without an understanding of Devayuga, the significance or the concept of śakti-yuga can never be understood.