“Long hours of labour seem to be the secret of the rational and healthful processes, which are to raise the condition of the labourer by an improvement of his mental and moral powers and to make a rational consumer out of him.”

Source: (1776), Book I, Chapter I, p. 7

Vol. II, Ch. XIX, p. 384.
(Buch II) (1893)

Source: The principles of political economy, 1825, p. 55-56 ;

De toutes les définitions de l'homme, la plus mauvaise me paraît celle qui en fait un animal raisonnable.
Le Petit Pierre (1918), ch. XXXIII

The Transhumanism Handbook, 2019

Preface to the Third Edition (August 1942)
The Mass Psychology of Fascism (1933)
Context: If, by being revolutionary, one means rational rebellion against intolerable social conditions, if, by being radical, one means "going to the root of things," the rational will to improve them, then fascism is never revolutionary. True, it may have the aspect of revolutionary emotions. But one would not call that physician revolutionary who proceeds against a disease with violent cursing but the other who quietly, courageously and conscientiously studies and fights the causes of the disease. Fascist rebelliousness always occurs where fear of the truth turns a revolutionary emotion into illusions.

Vol. II, Ch. III, p. 95.
Das Kapital (Buch II) (1893)

Art and Socialism (1884)

Introduction and Plan of the Work, p. 1.
(1776)