Lord Krishna speaks to Arjuna as he clarifies the origin and purpose of the caste system in sanaatana dharma (Bhagavad Gita, Chapter 4, Shloka 13).
cāturvarṇyaṃ mayā sṛṣṭaṃ guṇakarmavibhāgaśaḥ .
tasya kartāramapi māṃ viddhyakartāramavyayam .. BG 4\-13..
चातुर्वर्णयं मया सृष्टं गुणकर्मविभागशः ।
तस्य कर्तारमपि मां विद्ध्यर्कतारमव्ययम् ।। ४\-१३
Hindu society’s four-fold order
The four-fold order was created by Me according to the divisions of quality and work. Though I am its creator, know Me to be incapable of action or change.
Cāturvarṇyaṃ: the four-fold order. The four varnas are named – Brahmin, Kshatriya, Vaishya and Shudra. They constitute the four-fold order. The three gunas – sattva, rajas and tamas – and the law of karma – these four elements were divided by Me to create the four varnas.
Sattva guna predominates in Brahmins – and they are assigned the tasks (karma) of sham, dam, tapas (meditation) etc.
Rajas guna predominates in Kshatriyas – sattva guna is secondary. Their karma is to be warriors and show bravery and tejas.
Rajas guna also predominates in Vaishyas – tamas guna is secondary. Their karma is to be farmers and traders.
Tamas guna predominates in Vaishyas – rajas guna is secondary. Their karma is to serve others.
The emphasis is on temperament – not birth!
The emphasis is on guna (aptitude) and karma (function) and not on jaati (birth). The varna or the order to which we belong is independent of sex, birth or breeding. A varna is determined by temperament and vocation – not by birth or heredity.
According to the Mahabharata, the whole world was originally of one class but later it became divided into four divisions on account of the specific duties.
एकवर्णम इदम पूर्व विश्वम आसिद युधिश्ठिर कर्मक्रियाविशेसेन चतुर्वर्ण्यम प्रतिश्ठितम
ekavarṇama idama pūrvaṃ viśvama āsida yudhiśthira karmakriyāviśesena caturvarṇyama pratiśthitama
The Brahmin and outcaste are brothers
Even the distinction between caste and outcaste is artificial and unspiritual. An ancient verse points out that the Brahmin and the outcaste are blood brothers.