“Any child who cannot do long division by himself does not deserve to smoke.”

Light (1919), Ch. XVI - De Profundis Clamavi
Context: We cannot say out of what historical conjunctions the final tempests will issue, nor by what fancy names the interchangeable ideals imposed on men will be known in that moment. But the cause — that will perhaps everywhere be fear of the nations' real freedom. What we do know is that the tempests will come.
Armaments will increase every year amid dizzy enthusiasm. The relentless torture of precision seizes me. We do three years of military training; our children will do five, they will do ten. We pay two thousand million francs a year in preparation for war; we shall pay twenty, we shall pay fifty thousand millions. All that we have will be taken; it will be robbery, insolvency, bankruptcy. War kills wealth as it does men; it goes away in ruins and smoke, and one cannot fabricate gold any more than soldiers. We no longer know how to count; we no longer know anything. A billion — a million millions — the word appears to me printed on the emptiness of things. It sprang yesterday out of war, and I shrink in dismay from the new, incomprehensible word.
There will be nothing else on the earth but preparation for war. All living forces will be absorbed by it; it will monopolize all discovery, all science, all imagination.

Source: The Virtue of Selfishness: A New Concept of Egoism

Source: War and Peace

Book I, Ch. 42
Essais (1595), Book I

The Notebooks of Leonardo Da Vinci (1938), I Philosophy

Source: Words of Radiance

21 November 1917
Variant translation: Anyone who believes cannot experience miracles. By day one cannot see any stars.
The Blue Octavo Notebooks (1954)