Brahmanism is an early form of Hinduism which developed its worship and philosophy from the Vedas. Over years, the more tolerant and socially mobile system of Hindu society was ppressurisedinto a rigid caste system and the more liberal mystic Vedism was reduced to a complex sacerdotalism. Brahmanism, which is called “proto-Hinduism” by some, soon saw the traditionally elevated Brahmin caste as hereditary clergy.
It was only around three thousand years ago, with the advent of a group of thinkers who expounded on early Vedic monist and mystic leanings within the Vedas to produce the Upanishads that Brahminism saw challenges from schools of thought that came to form Classical Hinduism, otherwise seen as the six schools of Hindu or Vedic philosophy.
The Vedic line, which saw its nascence with the Aryan Brahminic schools, progressed into the Samkhya, Nyaya, Vaisheshika, Vedanta and Yoga schools, drawing from the rich Vedic canon of symbolism, philosophy theology and cosmology, as well as retaining Vedic gods or melding them with non-Vedic figures to create composites, like Shiva and Vishnu. The Purva Mimamsa school is the closest, albeit reformed, version of early Brahminism which sought to retain a puritan Vedic ritual and philosophical system, keeping alive such practices as the homa / fire ritual and worship of ancient Vedic gods like Indra, Agni and Varuna.
Some scholars, like Romila Thapar, would argue a discontinuance between Brahminism and later schools of Hinduism, but the retaining of the Vedas and Upanishads as spiritual fountainheads, the continuance of many customs and beliefs, and the acceptance of Vedic authority by later Hindus attest to an unbroken legacy that goes back over 4,000 years.
According to the Vishnusmriti (2-1.17)
“A Brahmin teaches the Veda… A Brahmin sacrifices for others, and receives alms… Duties common to all castes are… reverence towards gods and Brahmins.”
The tendency towards a comprehension of the unity of the divine essence had resulted in some minds, as has been remarked before, in a kind of monotheistic notion of the origin of the universe. In the literature of the Brahman period we meet with this conception as a common element of speculation; and so far from its being considered incompatible with the existence of a universal spirit, Prajapati, the personal creator of the world, is generally allowed a prominent place in the pantheistic theories. Yet the state of theological speculation, reflected in these writings, is one of transition.
The general drift of thought is essentially pantheistic, but it is far from being reduced to a regular system, and the ancient form of belief still enters largely into it. The attributes of Prajapati, in the same way, have in them elements of a purely polytheistic nature, and some of the attempts at reconciling this new-fangled deity with the traditional belief are somewhat awkward.
An ancient classification of the gods represented them as being thirty-three in number, eleven in each of the three worlds or regions of nature. These regions being associated each with the name of one principal deity, this division gave rise at a later time to the notion of a kind of triple divine government, consisting of Agni (fire) Indra (sky) or Vayu (wind), and Sirya (sun), as presiding respectively over the gods on earth, in the atmosphere, and in the sky.
Of this Vedic triad mention is frequently made in the Brahman writings. On the other hand the term prajapati (lord of creatures), which in the Rig Veda occurs as an epithet of the sun, is also once in the Atharvaveda applied jointly to Indra and Agni. Prajapati is several times mentioned as the thirty-fourth god; whilst in one passage he is called the fourth god, and made to rule over the three worlds. More frequently, however, the writings of this period represent him as the maker of the world and the father or creator of the gods. It is clear from this discordance of opinion on so important a point of doctrine, that at this time no authoritative system of belief had been agreed upon by the theologians. Yet there are unmistakable signs of a strong tendency towards constructing one, and it is possible that in yielding to it the Brahmans may have been partly prompted by political considerations.