You are totally wrong. jAti was by birth and varNa was by occupation. jAtis themselves moved up and down the hierarchy of varNa ladder.
Do you mean to say that there was a jati brahmana and a varna brahmana at any point of time? Was there a mechanism that was used to distinguish this? And how was it followed and, if abandoned, when and why?
A raThakAra, a chariot maker was a high status person during rg vedic times and in fact hymns were composed in his honour, example RV 1.6.32. In rAjasUya fire sacrifices, he was the PRINCIPAL RECEPIENT of the offerings. By contrast, during mahABhAratjA times, the particular varna had moved down the scale considerably.
I have a book where the following quote from the shanthi parva of Mahabharatha where Bharadwaj rishi is said to ask as follows:
Svedamoothra pureeshaani shleshma pittam sadhonitam.
Tanuh ksharati sarvedham kasmaad varno vibhajyate.
The meaning given as follows: But every human body bleeds, defecates, sweats, and has phlegm and life, alike. How can the human beings then be divided into varna of different colours?
Kamah krodho bhayam lobhah shokashchinta kshudha shramah.
sarvedham nah prabhavati kasmaad varno vibhidhyate.
Desire, anger, fear, greed, sorrow, anxiety, and hunger affect all human beings alike. How can there be then this difference of varna at all?
Contrary to popular perception and much cyber notes in internet, a Shudra was entitled to be a "yajamanan" for a fire sacrifice. He cannot perform the sacrifice himself but he sure could get it performed.
It is in no way different from the present day practice, where a BRAHMIN cant go to a temple to perform the pUjA himself, no matter how eligible and better qualified he is than the pUjari, but has to get the pUja or archanai performed by the pUjari. But it is not kosher to call this present day practice as "exploitation" nor is it politically expedient or correct to do so.
The yaksha asks yudhishtra:
Rajan kulena vrttena svaadhyaayena shrutena vaa.
Brahmanyam kena bhavati prabroohyotat sunishchatam.
Finally, profession, studies in scriptures, and philosophy of these, which determines brahminhood? Tell me definitely?
Yudhishtra replies:
shrunu yaksha kulam taata na svaadhyaayo na cha shrutam.
Kaaranam hi dvijatve cha vrttmeva na samshayaha.
Brahmanahood is determined by conduct and not by family, nor by studies, nor by listening to scriptures - of this there is no doubt.
We rarely see this followed. And this possibly must have been a shift in thinking of that period. Even as yudhishtra says this, we see contradictory examples followed in his period.
I think "brahminhood" must have been very much the subject of debate from times of yore, such as we are doing even now. It is not clearly established as to who is a brahmin, but going by practice, it is by birth alone.
