Are there statements in scriptures (not necessarily by those who might have felt oppressed and/or disdvantaged) that the caste-system was iniquitous?
I am looking for some parallel to the denunciation of anti-semitism in Shakespeare's Merchant of Venice:
Hath not a Jew hands, organs, dimensions, senses, affections, passions; fed with the same food, hurt with the same weapons, subject to the same diseases, healed by the same means, warmed and cooled by the same winter and summer as a Christian is? If you prick us, do we not bleed? If you tickle us, do we not laugh?"
The scriptures seem to have been under the control of the upper castes and its hard to find lamentations like that of Shylock in them.
There ARE statements that the aim of caste is not purely caste-based discrimination - but they seem to be minority views - please see:
The problem with this kind of selective interpretation is the fact that Hindu scripture contains many more verses (by more than two orders of magnitude) supporting ideas of caste-based discrimination (as in the stories of Matanga, Karna, or Shambuka) than they do verses along the lines of Shiva’s statement above. To take a decidedly minority view and present it as the authentic view of Hinduism is intellectually dishonest.
In addition, as I have pointed out from the beginning, the very fact that stories such as Matanga’s, Karna’s and Shambuka’s are prominently highlighted in Hindu scripture means that Hindu scripture can be used to support caste-based discrimination. In other words, a Hindu seeking to indulge in caste-based discrimination will find plenty of material, such as the story of Matanga or that of Karna or Shambuka, to justify his stand.