Brahmans the first and foremost caste of Hindu Society and its Caste System is the most talented intellectual class. They were known as Maharishies in the ancient times, who led a very austric life in the meditation, the dhyan yoga and tapasya. They gave Vedas and Upanishads and other ancient religious or spiritual literature. Brahmans are the descendents of these Maha-rishies, who are their gotras and parvars. The Caste System is oftenly being criticised by some without going deep in its merits and demerits. It is actually based on principle of Division of Labour. Considering the society as a whole just like human body.
Brahmans being intellectual class occupy the place of head or brain with their higher intellect, knowledge and understanding. Khatries as arm which is meant for protection of the body. Vaish or Merchant class are just like stomach, which receives food, digests and transforms into blood and circulates it through out the entire body. They are supposed to bring the every day use commodities from their place of origin, where they are produced and supplied to the society with reasonable price including costs and theirs normal profit. The Shudras are not un-touchable, But labourers, a very important class responsible for production in the Country.
They are thus compared with legs upon which the entire structure of the society stands. The caste is determined by two factors Birth and Action or Karam after Birth to maintain it. Theory of Karma or Transmigration of Soul clearly shows that caste in which Jiva gets birth is determined by the Prarbadh Karams, which mature at the time of his birth. Jivatma gets birth due to his past good deeds and as a Brahman he still needs much more good deeds or Karmas. Only individual souls with best past record of good karmas can get birth as Brahmans. After birth the second and the most important factor is the action or Karma performed by the individual. By combination of two completes the determination of Varans or caste of individual.