I think the most important factor moving us toward a secular society has been the educational factor. Our schools may not teach Johnny to read properly, but the fact that Johnny is in school until he is sixteen tends toward the elimination of religious superstition.
Religious liberty in a nation is as real as the liberty of its least popular religious minority. Look not to the size of cathedrals or even to the words on the statute books for proof of the reality of religious freedom. Ask what is the fate of the Protestant in Spain, the Jew in Saudi Arabia, the Arab in Israel, the Catholic in Poland or the atheist in the United States.
In religious matters it is now fashionable to define tolerance as the absence of criticism of any standard religion. All too often, this absence of criticism degenerates into a conspicuous absence of thought.