What really differentiates a class society from a caste society...? Try like so: you can establish a caste society by excluding or refusing a group the culture or status of another, thereby permanently separating the two.
Refusing to admit any existing differences within a society, what some might call a society of the individual, surely infinitely better than one that dares classify those living in it and hence glorious, forces us to treat, judge, punish, reward, perceive everyone alike and ultimately disintegrates social networks and exactly what it seeks to protect: our identity. What follows are real, existing social groups denied to identify their identity making it impossible for them to adapt or change their status within the society. Like in a caste society where your family of birth will set in stone your future, a class denied it's existence is thus forever doomed to imaginary similarity with an upper (or lower) class and will become immobile.
