The proliferation from four varnas to four thousand castes proves chaturvarnya classification failed.

Evidence

All this is demonstrably wrong. Modern science has shown that the lumping together of individuals into a few sharply marked-off classes is a superficial view of man, not worthy of serious consideration. Consequently, the utilisation of the qualities of individuals is incompatible with their stratification by classes, since the qualities of individuals are so variable. Chaturvarnya must fail for the very reason for which Plato’s Republic must fail—namely, that it is not possible to pigeon men into holes according to class. That it is impossible to accurately classify people into four definite classes is proved by the fact that the original four classes have now become four thousand castes. — Ambedkar, B R, Annihilation of Caste_ The Annotated…, 918

Categorization

• DEEPTHINKING: The empirical proof — four classes became four thousand castes because accurate classification is impossible — is the chapter’s most powerful causal argument.