“Ignorance immediately knows things in an ordinary, conceptual way. Because ignorance and its accompanying mental states arise first, wrong beliefs ensue. Therefore the texts say, "Ignorance conceals the true nature of obejcts."”

Guru Nanak quotes

Fragment 109
Variant translation: Hide our ignorance as we will, an evening of wine soon reveals it.
Numbered fragments

The Notebooks of Leonardo da Vinci (1883), XIX Philosophical Maxims. Morals. Polemics and Speculations.

"Niagara Movement Speech" (1905) http://teachingamericanhistory.org/library/document/niagara-movement-speech/ <!--originally a portion of this was cited here to an Address to the Nation speech at Harpers Ferry, Virginia (16 August 1906); published in the New York Times on (20 August 1906) — but that does not correspond with the info at the link. -->
Context: The school system in the country districts of the South is a disgrace and in few towns and cities are Negro schools what they ought to be. We want the national government to step in and wipe out illiteracy in the South. Either the United States will destroy ignorance or ignorance will destroy the United States.
And when we call for education we mean real education. We believe in work. We ourselves are workers, but work is not necessarily education. Education is the development of power and ideal. We want our children trained as intelligent human beings should be, and we will fight for all time against any proposal to educate black boys and girls simply as servants and underlings, or simply for the use of other people. They have a right to know, to think, to aspire.
These are some of the chief things which we want. How shall we get them? By voting where we may vote, by persistent, unceasing agitation; by hammering at the truth, by sacrifice and work.
We do not believe in violence, neither in the despised violence of the raid nor the lauded violence of the soldier, nor the barbarous violence of the mob, but we do believe in John Brown, in that incarnate spirit of justice, that hatred of a lie, that willingness to sacrifice money, reputation, and life itself on the altar of right. And here on the scene of John Brown’s martyrdom we reconsecrate ourselves, our honor, our property to the final emancipation of the race which John Brown died to make free.
Our enemies, triumphant for the present, are fighting the stars in their courses. Justice and humanity must prevail.

Letter to Lord Kennet, 1941; cited from Ursula Vaughan Williams RVW (1964) p. 243.

address " What is Science? http://www.fotuva.org/feynman/what_is_science.html", presented at the fifteenth annual meeting of the National Science Teachers Association, in New York City (1966), published in The Physics Teacher, volume 7, issue 6 (1969), p. 313-320

In p. 144.
Sources, The Yoga Darsana Of Patanjali With The Sankhya Pravacana Commentary Of Vyasa

Source: The Wise Man's Fear