A nation that enslaves another forges its own chains.

In proportion therefore, as the repulsiveness of the work increases, the wage decreases.

Social progress can be measured exactly by the social position of the fair sex.

In communist society, where nobody has one exclusive sphere of activity but each can become accomplished in any branch he wishes, society regulates the general production and thus makes it possible for me to do one thing today and another tomorrow, to hunt in the morning, fish in the afternoon, rear cattle in the evening, criticize after dinner, just as I have a mind, without ever becoming hunter, fisherman, shepherd or critic.

The proletarians have nothing to loose but their chains. They have a world to win.

...it happens that society is saved as often as the circle of its ruling class is narrowed, as often as a more exclusive interest asserts itself over the general. Every demand for the most simple bourgeois financial reform, for the most ordinary liberalism, for the most commonplace republicanism, for the flattest democracy is forthwith punished as an assault upon society and is branded as Socialism.

There is no royal road to science, and only those who do not dread the fatiguing climb of its steep paths have a chance of gaining its luminous summits. (Preface to the French edition).