In an article on Bunyan lately published in the "Contemporary Review" - the only article on the subject worth reading on the subject I ever saw (yes, thank you, I am familiar with Macaulay's patronizing prattle about "The Pilgrim's Progress") etc.
All censorships exist to prevent anyone from challenging current conceptions and existing institutions. All progress is initiated by challenging current conceptions, and executed by supplanting existing institutions. Consequently, the first condition of progress is the removal of censorship.
Chemistry ceases to improve when one element is found from which all others are deductible. Physics ceases to progress when one force is found of which all others are manifestations. So religion ceases to progress when unity is reached, which is the case with Hinduism.
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.