I will read this tomorrow.
Caste, or varna in Sanskrit, was already in existence 5000 years ago when Bhagavad Gita was spoken. It was also understood as described in the Puranas to be actually based on quality and characteristics or abilities and not on birth, although usually people born in a specific varna or caste would stay in it, but there were many exceptions. There is very little understanding of the actual varna/caste system and its benefits.
“Caste” is a foreign word to India — it is not found in Sanskrit. “Caste” is often confused with “varna” which is really the “color of the mind”, signifying inclination, natural tendency or propensity.