“The only knowledge that can truly orient action is knowledge that frees itself from mere human interests and is based in Ideas—in other words knowledge that has taken a theoretical attitude.”

On Practice (1937)

Choruses from The Rock (1934)
Context: O perpetual revolution of configured stars,
O perpetual recurrence of determined seasons,
O world of spring and autumn, birth and dying!
The endless cycle of idea and action,
Endless invention, endless experiment,
Brings knowledge of motion, but not of stillness;
Knowledge of speech, but not of silence;
Knowledge of words, and ignorance of The Word.
All our knowledge brings us nearer to our ignorance,
All our ignorance brings us nearer to death,
But nearness to death no nearer to God.
Where is the Life we have lost in living?
Where is the wisdom we have lost in knowledge?
Where is the knowledge we have lost in information?
The cycles of Heaven in twenty centuries
Brings us farther from God and nearer to the Dust.

Die Scheu vor der Spekulation, das angebliche Forteilen vom bloß Theoretischen zum Praktischen, bewirkt im Handeln notwendig die gleiche Flachheit wie im Wissen. Das Studium einer streng theoretischen Philosophie macht uns am unmittelbarsten mit Ideen vertraut, und nur Ideen geben dem Handeln Nachdruck und sittliche Bedeutung.
Vorlesungen über die Methode des akademischen Studiums ( Seventh Lecture http://www.zeno.org/Philosophie/M/Schelling,+Friedrich+Wilhelm+Joseph/Vorlesungen+%C3%BCber+die+Methode+des+akademischen+Studiums/7.+%C3%9Cber+einige+%C3%A4u%C3%9Fere+Gegens%C3%A4tze+der+Philosophie,+vornehmlich+den+der+positiven+Wissenschaften), Friedrich Wilhelm Joseph von Schellings sämmtliche Werke, V, 1859, p. 277 http://babel.hathitrust.org/cgi/pt?q1=%22nur%20Ideen%20geben%22;id=uva.x002624295;view=1up;seq=301;start=1;sz=10;page=search;num=277.
On University Studies (1803)

The New Economics for Industry, Government, Education (1993)

Source: Ink and Bone

Address at Princeton University, "The Educated Citizen" (22 March 1954) http://infoshare1.princeton.edu/libraries/firestone/rbsc/mudd/online_ex/stevenson/adlai1954.html
Context: What a man knows at fifty that he did not know at twenty is, for the most part, incommunicable. The laws, the aphorisms, the generalizations, the universal truths, the parables and the old saws — all of the observations about life which can be communicated handily in ready, verbal packages — are as well known to a man at twenty who has been attentive as to a man at fifty. He has been told them all, he has read them all, and he has probably repeated them all before he graduates from college; but he has not lived them all.
What he knows at fifty that he did not know at twenty boils down to something like this: The knowledge he has acquired with age is not the knowledge of formulas, or forms of words, but of people, places, actions — a knowledge not gained by words but by touch, sight, sound, victories, failures, sleeplessness, devotion, love — the human experiences and emotions of this earth and of oneself and other men; and perhaps, too, a little faith, and a little reverence for things you cannot see.

The Spirit of Revolt (1880)
Context: Whoever has a slight knowledge of history and a fairly clear head knows perfectly well from the beginning that theoretical propaganda for revolution will necessarily express itself in action long before the theoreticians have decided that the moment to act has come. Nevertheless, the cautious theoreticians are angry at these madmen, they excommunicate them, they anathematize them. But the madmen win sympathy, the mass of the people secretly applaud their courage, and they find imitators. In proportion as the pioneers go to fill the jails and the penal colonies, others continue their work; acts of illegal protest, of revolt, of vengeance, multiply.
Indifference from this point on is impossible. Those who at the beginning never so much as asked what the "madmen" wanted, are compelled to think about them, to discuss their ideas, to take sides for or against. By actions which compel general attention, the new idea seeps into people's minds and wins converts. One such act may, in a few days, make more propaganda than thousands of pamphlets.
Above all, it awakens the spirit of revolt: it breeds daring. The old order, supported by the police, the magistrates, the gendarmes and the soldiers, appeared unshakable, like the old fortress of the Bastille, which also appeared impregnable to the eyes of the unarmed people gathered beneath its high walls equipped with loaded cannon. But soon it became apparent that the established order has not the force one had supposed.

Introduction
Popular Astronomy: A Series of Lectures Delivered at Ipswich (1868)

Source: The Unfinished System of Nonknowledge