Coming to the Indian milieu we find Plato’s three categories split into four “varnas” (singular is varna, meaning colour, category, class or the profession that we adopt, depending upon the word’s reference to context).
The earliest reference to the varna is found in the Purush Shukta of the Rigveda (Rigveda 10.90.11 & 12) and it echoes repeatedly in
Yajurveda 31.10 &11,
Atharvaveda 19.6.5 & 6.
Bagwatagita and Manu Smriti.
The very first Census of British India, carried out in 1871-72, toed this line of “fourfold division of Hindoos” : Brahamins, Kshatriyas/Rajputs, Vaishyas and Shudras.
The Brahamins are considered the fountainhead of the esotericism in India.
According to the Memorandum on the Census of British India of 1871-72 — an introduction to the Census — submitted to the British Parliament, the Census surveyed the population based on the categories of age, sex, caste, religion, education, occupation, dwelling, infirmity, nationality, language, and location (rural or urban). It mentioned the incidence of female infanticide, provided detailed information about various castes (from “superior” and “intermediate” to “agricultural” and “labouring”), and gave figures for revenue collected per acre of land and per adult male agriculturalist.
The Memorandum was written by Henry Waterfield, a civil servant of that era. Waterfield worked for 44 years with the India Office, that is, the British government department that supervised the administration of the provinces directly under British governance.
The Census stirred up some controversy in India as some modern authors, such as Bernard S. Cohn and Nicholas B. Dirks, argued that the British, through their Census and other works, created the caste system as it exists today. However the Indian authors debunked their theory and acknowledged that the four-fold categories, or the castes, existed much before the British came to India.
Nevertheless the fact remains that this broad four-fold categorisation did not apply throughout the country. For example in Punjab the Brahmanic system had no practical purpose from an administrative point of view. In 1881, Punjab abandoned the primary categorisation by varna that was used in other British Indian jurisdictions in that year, preferring instead to assign more weight to the category of occupation. Similarly, many southern states differed from this “four-fold division of Hindoos.”
Manu Smriti
An elaborate description of the varnas is given by Manu in his Manu Smiriti where he describes at length the various duties of the Brahamins, Kshatriyas, Vaishya and the Shudras. The Brahamins according to the attributes given by Manu are closest to the Philosophers-Kings described by Plato in The Republic. The Kshatriyas, are the Auxiliaries or the warriors who are meant to defend the country while the Vaishya and the Shudra have been clubbed together to form the group described by Plato as the Producers.
The reason d’etre of this close similarity between Plato’s three categories in The Republic and the four varnas of the Hindu system is obviously the perceived division of labour in a society — any society — past or present.
Every society has to have a religion, a set of value-system that lends moral backbone to the entire edifice of the society. The fountainhead of such a religious-moral belief is the priest — the custodian of morality. Plato assigned this role to the Guardians while Manu gave the role to Brahamins.
Next in Manu’s priority list came the Kshatriyas. Every nation/state has to have a robust defence mechanism and hence the need for a army of Plato’s Auxiliaries — the warriors — or we may call them the Kshatriyas.
What Plato called the Producers came next — the class of people that run the business/industrial lifeline of the nation. To this you may include the goods and services sector and you get the entire gamut of social activity that Plato’s Producer class was meant for. Manu in India split this class into two castes, the Vaishyas and the Shudras. Broadly, the Vaishyas took care of the business and industry while the service sector was handled by the Shudras.
There is no reason to blame Manu for the caste division, or to curse Plato for creating three distinct classes — the very concept of division of labour necessitates division of a society into multiple groups in accordance with the profession they pursue. In fact there can be no State or an ordered society without distinct stratification of its citizens, only the nomenclature varies from place to place and time to time.