This question already has an answer here:
In Gita there is also caste system. May be it was for the stability of the society. My question : A son of a sudra may have potential to become a bramhin.( I mean to say that he may have more brain capacity and may contribute more to Hinduism by writing some philosophy). So wasn't it unfair for that sudra's son? I think this is a waste of talent. I also think god also don't want that, that is why caste system is not rigid nowadays.