Social progress takes effect through the replacement of all institutions by new ones; and since every institution involves the recognition of the duty of conforming to it, progress must involve the repudiation of an established duty at every step.
It is a mark of wisdom not to kick away the very step from which we have risen higher. The removal of one step from a staircase brings down the whole of it.
Whenever the strength of a belief strongly steps into the foreground, we must infer a certain weakness of demonstrability and the improbability of that belief.