The Four Castes of Hindudharam

In Bhavishya Puran, Ved Vayas ji started the predictions from the event of Adam's birth. It shows that Puranas were prior to Adam.
Adam was born 2208 years before the end of Duaper yuga. Today, 2208+5070=7278 years have passed after Adam.
Prior to Adam, there were 4 Varna (castes) which were made in accordance with the characters and deeds.
Rig Ved indicateds 4 names, assighed to them in this respect.
• Brahmana Varna
• Kshatriya Varna
• Vaishya Varna
• Shudra Varna

The system of four varnas was said to have been created by Sri Krishna as stated in the Bhagavad-Gita 4.13:
cātur-varṇyaḿ mayā sṛṣṭaḿ guṇa-karma-vibhāgaśaḥ
tasya kartāram api māḿ viddhy akartāram avyayam
"The four orders of society were created by Me classifying them according to the mode of Parkriti predominant in each and apportioning corresponding duties to them; though the author of this creation, know Me, the immortal Lord, to be a non-doer."
The varna system is also mentioned in the Purusha sukta of Rigveda 10.90.12 which states:
"The Brahmana was the mouth of the purusha, his two arms were made into the Rajanya, his two thighs were the Vaishya, and from his two feet the Shudra was born."

1- From Bhagavad-gita 18.42:
śamo damas tapaḥ śaucaḿ kṣāntir ārjavam eva ca
jñānaḿ vijñānam āstikyaḿ brahma-karma svabhāva-jam
Brahmanas are said to have made from the face of the Purusha. They posses the qualities like: Purity, Peace-loving, self-control, tolerance, austerity, honesty, knowledge and wisdom.

2- From Bhagavad-gita 18.43:
śauryaḿ tejo dhṛtir dākṣyaḿ yuddhe cāpy apalāyanam
dānam īśvara-bhāvaś ca kṣātraḿ karma svabhāva-jam
Kshatriyas are said to have been created from the limbs of Purusha, indicating the ability to act. He was a fighter for maintaining peace or soldier.

3- Vaishyas, ccording to Manu-smriti, have come from the belly of Brahma. So they have to work to fill up the belly. Primarily, they were artisans, cattle-bearers and merchants. Eventually became land-owners, money-lenders and influential traders.

4- The Bhagavata Purana 11.17.21 states about Shudra Varna:
ahiḿsā satyam asteyam akāma-krodha-lobhatā
bhūta-priya-hitehā ca dharmo 'yaḿ sārva-varṇikaḥ
"Nonviolence, truthfulness, honesty, desire for the happiness and welfare of all others and freedom from lust, anger and greed constitute duties for all members of society."
Moreover, according to Bhagavata Purana 11.17.20:
aśaucam anṛtaḿ steyaḿ nāstikyaḿ śuṣka-vigrahaḥ
kāmaḥ krodhaś ca tarṣaś ca sa bhāvo 'ntyāvasāyinām
"Dirtiness, dishonesty, thievery, faithlessness, useless quarrel, lust, anger and hankering constitute the nature of those in the lowest position outside the varṇāśrama system."
So they are the lowest verna, the only un-touchable of the Indian society, a hateful face of the Indian culture.
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