One quote from his 1978 Harvard Commencement address:
However, in early democracies, as in the American democracy at the time of its birth, all individual human rights were granted because man is God's creature. That is, freedom was given to the individual conditionally, in the assumption of his constant religious responsibility. Such was the heritage of the preceding thousand years. Two hundred or even fifty years ago, it would have seemed quite impossible, in America, that an individual could be granted boundless freedom simply for the satisfaction of his instincts or whims. Subsequently, however, all such limitations were discarded everywhere in the West; a total liberation occurred from the moral heritage of Christian centuries with their great reserves of mercy and sacrifice. State systems were -- State systems were becoming increasingly and totally materialistic. The West ended up by truly enforcing human rights, sometimes even excessively, but man's sense of responsibility to God and society grew dimmer and dimmer. In the past decades, the legalistically selfish aspect of Western approach and thinking has reached its final dimension and the world wound up in a harsh spiritual crisis and a political impasse. All the glorified technological achievements of Progress, including the conquest of outer space, do not redeem the 20th century's moral poverty which no one could imagine even as late as in the 19th Century.
As humanism in its development became more and more materialistic, it made itself increasingly accessible to speculation and manipulation by socialism and then by communism. So that Karl Marx was able to say that "communism is naturalized humanism."
This statement turned out not to be entirely senseless. One does see the same stones in the foundations of a despiritualized humanism and of any type of socialism: endless materialism; freedom from religion and religious responsibility, which under communist regimes reach the stage of anti-religious dictatorships; concentration on social structures with a seemingly scientific approach. This is typical of the Enlightenment in the 18th Century and of Marxism.
