One day we shall certainly 'reduce' thought experimentally to molecular and chemical motions in the brain; but does that exhaust the essence of thought?

Three hundred years after its appearance Christianity was the recognized state religion in the Roman World Empire, and in barely sixty years socialism has won itself a position which makes its victory absolutely certain.

The way in which the vast mass of the poor are treated by modern society is truly scandalous. They are herded into great cities where they breathe a fouler air than in the countryside which they have left.

If in all ideology men and their circumstances appear upside-down as in a camera obscura, this phenomenon arises just as much from their historical life-process as the inversion of objects on the retina does from the physical life-process.

It is no longer a question anywhere of inventing interconnections from out of our brains, but of discovering them in the facts.

All that is real in human history becomes irrational in the process of time.

Everything must justify its existence before the judgment seat of Reason, or give up existence.