The Annihilation of Caste by BR Ambedkar.

It's an excellent critique of Hinduism and reformist Hindus by one of the most celebrated and hated freedom fighters of India.

Ambedkar was a member of the oppressed Dalit caste who said the root of caste lay in Hinduism itself and not just a "few bad apples".

His most outspoken critic weren't the traditional orthodox upper caste Hindus but rather Mahatma Gandhi who accused him of "throwing the baby out with the bathwater".

Ambedkar was also critical of the communist/socialist parties and movements, considering them as class-reductionists. Caste, he argued, wasn't just a division of labor but of laborers themselves and caste divisions supersede any solidarity proletarians may have. The socialists weren't ready to put caste issues front and center as he demanded. Their differences have led to a massive split between the communists today and what is supposed to be their prime constituents - the hundreds of millions of oppressed Dalits, Adivasis etc.

Its a very interesting read that is extremely relevant to this day in the context of India and other Third World leftist projects.