Caste is not a physical object like a wall of bricks or a line of barbed wire which prevents the Hindus from co-mingling and which has, therefore, to be pulled down. Caste is a notion; it is a state of the mind.
barbed brick caste
These are some quotes by Indian author B. R. Ambedkar Politician, who lived between April 14, 1891 and December 6, 1956.