“Ignorance is an evil weed, which dictators may cultivate among their dupes, but which no democracy can afford among its citizens.”

1930s, Speech to the Democratic National Convention (1936)

Source: The Prince (1513), Ch. 14; translated by W. K. Marriot

Quotes:, Autobiography of Sir Henry Morton Stanley (1909)

Letter to http://memory.loc.gov/cgi-bin/query/r?ammem/mtj:@field(DOCID+@lit(tj110158)) Thomas Leiper (12 June 1815). Published in The Works of Thomas Jefferson in Twelve Volumes http://oll.libertyfund.org/ToC/0054.php, Federal Edition, Paul Leicester Ford, ed., New York: G. P. Putnam's Sons, 1904, Vol. 11 http://oll.libertyfund.org/Texts/Jefferson0136/Works/0054-11_Bk.pdf, pp. 477–478.
The sentence "I hope our wisdom will grow with our power, and teach us, that the less we use our power, the greater it will be." was used by US-President Barack Obama in his A New Beginning Speech.
1810s
Context: We concur in considering the government of England as totally without morality, insolent beyond bearing, inflated with vanity and ambition, aiming at the exclusive dominion of the sea, lost in corruption, of deep-rooted hatred towards us, hostile to liberty wherever it endeavors to show its head, and the eternal disturber of the peace of the world. In our estimate of Bonaparte, I suspect we differ. [... ] Our form of government is odious to him, as a standing contrast between republican and despotic rule; and as much from that hatred, as from ignorance in political economy, he had excluded intercourse between us and his people, by prohibiting the only articles they wanted from us, that is, cotton and tobacco. Whether the war we have had with England, and the achievements of that war, and the hope that we may become his instruments and partisans against that enemy, may induce him, in future, to tolerate our commercial intercourse with his people, is still to be seen. For my part, I wish that all nations may recover and retain their independence; that those which are overgrown may not advance beyond safe measures of power, that a salutary balance may be ever maintained among nations, and that our peace, commerce, and friendship, may be sought and cultivated by all. It is our business to manufacture for ourselves whatever we can, to keep our markets open for what we can spare or want; and the less we have to do with the amities or enmities of Europe, the better. Not in our day, but at no distant one, we may shake a rod over the heads of all, which may make the stoutest of them tremble. But I hope our wisdom will grow with our power, and teach us, that the less we use our power, the greater it will be.

Constitutional Convention http://avalon.law.yale.edu/18th_century/debates_531.asp Monday May 31 [FN1], 1787

Dan in Sotsiallistichesky Vestnik no. 17-18 about the Trotskyite opposition in the Soviet Union. Quote from Harpal Brar's Trotskyism or Leninism? p. 476.

Part I, Chapter III, The Problem of Conserving Surplus, p. 43 (italics as per text)
Storage and Stability (1937)

The Procedural Republic and the Unencumbered Self, 1984

The Kasîdah of Hâjî Abdû El-Yezdî (1870), Note I : Hâjî Abdû, The Man
Context: That creatures endowed with the mere possibility of liberty should not always choose the Good appears natural. But that of the milliards of human beings who have inhabited Earth, not one should have been found invariably to choose Good, proves how insufficient is the solution. Hence no one believes in the existence of the complete man under the present state of things. The Haji rejects all popular and mythical explanation by the Fall of "Adam," the innate depravity of human nature, and the absolute perfection of certain Incarnations, which argues their divinity. He can only wail over the prevalence of evil, assume its foundation to be error, and purpose to abate it by uprooting that Ignorance which bears and feeds it.
His "eschatology," like that of the Soofis generally, is vague and shadowy.