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).
Karl MarxLet the ruling classes tremble at a communist revolution. The proletarians have nothing to lose but their chains. They have a world to win. Workingmen of all countries, unite!
Karl MarxLabor, being itself a commodity, is measured as such by the labor time needed to produce the labor-commodity. And what is needed to produce this labor-commodity? Just enough labor time to produce the objects indispensable to the constant maintenance of labor, that is, to keep the worker alive and in a condition to propagate his race. The natural price of labor is no other than the wage minimum.
Karl Marx