The caste system (varnashrama) in India is and has been in the recent past a tool of oppression and abuse. However, the modern caste system does not follow (though it is descended from) the system of varnashrama originally laid out in the Vedas. This original vision was not inegalitarian, nor was it prescriptive. Rather, it was and is a description of roles that individuals play in society. According to the Vedas, these roles should ideally be determined by talent and self-determination rather than by birth and are all necessary and deserving of respect.
This is the role of the intellectual, the teacher or the priest: people with a high level of education and wisdom, who were fit to guide and teach others. Brahmins in early Indian society could be found teaching, performing rituals, and providing guidance and counseling to others. Given the high value Vedic society placed on knowledge, the role of the brahmin had considerable prestige and was considered the highest caste.
A kshatriya was one involved in either governance or military activities, either a ruler or a warrior. Kings and queens were kshatriyas, as were professional soldiers. The duty of a kshatriya was to protect the weak and helpless and to promote justice.
A vaishya was a merchant or an entrepreneur, anyone involved in trade or running a business. A vaishya's duty was to manage a successful business and promote trade and economic health in an honest and fair manner.
A shudra was anyone who worked with his or her hands. Shudras could be artisans, craftspeople, field laborers, cooks, servants-anything that involved manual labor. A shudra's duty was to do his or her work to the best of his or her ability and so help keep the community running smoothly. While shudras are often looked down on as the lowest caste, according to the Vedas their work is essential and they are as entitled to respect as the other castes.
Furthermore, varnashrama was meant to divide the assets integral to human society-learning, political power, wealth and skills-so that no one individual or group of individuals could possess them all and thus overtake the others. The goal was to create a balance of power, so that people could check and restrain anyone or any group who tried to seize excessive control over community affairs. For example, the kshatriyas would depend on the brahmins' advice and expertise to create policies, and on funding from the vaishyas to pay for those policies, and on the skills of the shudras to put those policies into action. Vedic society was collaborative, not competitive, and aimed at promoting the spiritual growth of each member rather than allowing a few members to dominate the others.