“It is always advisable to perceive clearly our ignorance.”

Pg. 23.
Against Method (1975)

"Game III," p. 98
The Sun Watches the Sun (1999), Sequence: “A Game”

Confessions of a Revolutionary (1849)
Context: It is necessary to have lived in this insulator which is called the national assembly, in order to perceive how the men who are the most completely ignorant of the state of the country are almost always the ones who represent it. I set myself to read everything that the distribution bureau sends the representatives: proposals, reports, brochures, even the Moniteur and the Bulletin of the laws. The greater part of my colleagues of the left and the extreme left were in the same perplexity of spirit, in the same ignorance of the daily facts. The national workshops were spoken of only with a kind of fright; for fear of the people is the defect of all those who belong to authority; the people, as concerns power, is the enemy.

As quoted in Thinking to Some Purpose (1939), Preface

Part 4, Section 7
A Treatise of Human Nature (1739-40), Book 1: Of the understanding
Context: This deficiency in our ideas is not, indeed, perceived in common life, nor are we sensible, that in the most usual conjunctions of cause and effect we are as ignorant of the ultimate principle, which binds them together, as in the most unusual and extraordinary. But this proceeds merely from an illusion of the imagination; and the question is, how far we ought to yield to these illusions. This question is very difficult, and reduces us to a very dangerous dilemma, whichever way we answer it. For if we assent to every trivial suggestion of the fancy; beside that these suggestions are often contrary to each other; they lead us into such errors, absurdities, and obscurities, that we must at last become asham'd of our credulity. Nothing is more dangerous to reason than the flights of the imagination, and nothing has been the occasion of more mistakes among philosophers. Men of bright fancies may in this respect be compar'd to those angels, whom the scripture represents as covering their eyes with their wings. This has already appear'd in so many instances, that we may spare ourselves the trouble of enlarging upon it any farther.

The Problem of Peace (1954)
Context: The only originality I claim is that for me this truth goes hand in hand with the intellectual certainty that the human spirit is capable of creating in our time a new mentality, an ethical mentality. Inspired by this certainty, I too proclaim this truth in the hope that my testimony may help to prevent its rejection as an admirable sentiment but a practical impossibility. Many a truth has lain unnoticed for a long time, ignored simply because no one perceived its potential for becoming reality.

Source: The Treasure of the City of Ladies