All the other large and small nationalities and peoples are destined to perish before long in the revolutionary world storm. The next world war will result in the disappearance from the face of the earth not only of reactionary classes and dynasties, but also of entire reactionary peoples. And that, too, is a step forward.

Ideas often kindle each other, like electrical sparks.

The free development of each is the condition for the free development of all.

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

Don't forget any affront done to you and to all our people, the time of revenge will come and must be put to good use.

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.

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