“When a spirit has reached the end of the term assigned by Providence to his errant life, he chooses for himself the trials which he determines to undergo in order to hasten his progress - that is to say, the kind of existence which he believes will be most likely to furnish him with the means of advancing and the trials of this new existence always correspond to the faults which he has to expiate. If he triumphs in this new struggle, he rises in grade; if he succumbs, he has to try again.”

Source: The Montessori Method (1912), Ch. 1 : A Critical Consideration of the New Pedagogy in its Relation to Modern Science, p. 8.
Context: We give the name scientist to the type of man who has felt experiment to be a means guiding him to search out the deep truth of life, to lift a veil from its fascinating secrets, and who, in this pursuit, has felt arising within him a love for the mysteries of nature, so passionate as to annihilate the thought of himself. The scientist is not the clever manipulator of instruments, he is the worshipper of nature and he bears the external symbols of his passion as does the follower of some religious order. To this body of real scientists belong those who, forgetting, like the Trappists of the Middle Ages, the world about them, live only in the laboratory, careless often in matters of food and dress because they no longer think of themselves; those who, through years of unwearied use of the microscope, become blind; those who in their scientific ardour inoculate themselves with tuberculosis germs; those who handle the excrement of cholera patients in their eagerness to learn the vehicle through which the diseases are transmitted; and those who, knowing that a certain chemical preparation may be an explosive, still persist in testing their theories at the risk of their lives. This is the spirit of the men of science, to whom nature freely reveals her secrets, crowning their labours with the glory of discovery.
There exists, then, the "spirit" of the scientist, a thing far above his mere "mechanical skill," and the scientist is at the height of his achievement when the spirit has triumphed over the mechanism. When he has reached this point, science will receive from him not only new revelations of nature, but philosophic syntheses of pure thought.

The Eighteenth Brumaire of Louis Bonaparte (1852)
Context: Men make their own history, but they do not make it as they please; they do not make it under self-selected circumstances, but under circumstances existing already, given and transmitted from the past. The tradition of all dead generations weighs like a nightmare on the brains of the living. And just as they seem to be occupied with revolutionizing themselves and things, creating something that did not exist before, precisely in such epochs of revolutionary crisis they anxiously conjure up the spirits of the past to their service, borrowing from them names, battle slogans, and costumes in order to present this new scene in world history in time-honored disguise and borrowed language. Thus Luther put on the mask of the Apostle Paul, the Revolution of 1789-1814 draped itself alternately in the guise of the Roman Republic and the Roman Empire, and the Revolution of 1848 knew nothing better to do than to parody, now 1789, now the revolutionary tradition of 1793-95. In like manner, the beginner who has learned a new language always translates it back into his mother tongue, but he assimilates the spirit of the new language and expresses himself freely in it only when he moves in it without recalling the old and when he forgets his native tongue.
When we think about this conjuring up of the dead of world history, a salient difference reveals itself. Camille Desmoulins, Danton, Robespierre, St. Just, Napoleon, the heroes as well as the parties and the masses of the old French Revolution, performed the task of their time – that of unchaining and establishing modern bourgeois society – in Roman costumes and with Roman phrases.

Third Thesis
Idea for a Universal History from a Cosmopolitan Point of View (1784)

Source: Man for Himself (1947), Ch. 3 "Human Nature and Character

Source: Democracy in America, Volume I (1835), Chapter I-V, Chapter V.

§ IV
1910s, At the Feet of the Master (1911)
Context: These three great crimes you must avoid, for they are fatal to all progress, because they sin against love. But not only must you thus refrain from evil; you must be active in doing good. You must be so filled with the intense desire of service that you are ever on the watch to render it to all around you — not to man alone, but even to animals and plants. You must render it in small things every day, that the habit may be formed, so that you may not miss the rare opportunity when the great thing offers itself to be done. For if you yearn to be one with God, it is not for your own sake; it is that you may be a channel through which His love may flow to reach your fellow-men.
He who is on the Path exists not for himself, but for others; he has forgotten himself, in order that he may serve them. He is as a pen in the hand of God, through which His thought may flow, and find for itself an expression down here, which without a pen it could not have. Yet at the same time he is also a living plume of fire, raying out upon the world the Divine Love which fills his heart.
The wisdom which enables you to help, the will which directs the wisdom, the love which inspires the will — these are your qualifications. Will, Wisdom and Love are the three aspects of the Logos; and you, who wish to enroll yourselves to serve Him, must show forth these aspects in the world.

Source: Treason of the Intellectuals (1927), pp. 158–159

the first lines in 'Manifesto du Surréalisme', Andre Breton, 1924
Le Manifeste du Surréalisme, Andre Breton (Manifesto of Surrealism; 1924)