“I believe it is an established maxim in morals that he who makes an assertion without knowing whether it is true or false, is guilty of falsehood; and the accidental truth of the assertion, does not justify or excuse him.”
Letter to Allen N. Ford (11 August 1846), reported in Roy Prentice Basler, ed., Abraham Lincoln: His Speeches and Writings (1990 [1946])
1840s
Help us to complete the source, original and additional information
Abraham Lincoln 618
16th President of the United States 1809–1865Related quotes

Source: A Way to Be Free: The Autobiography of Robert LeFevre, Volume I, (1999), p. 19

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 290.

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 606.

Twitter post, https://twitter.com/neiltyson/status/350753146445893633 (2015-03-03)
2010s

In Re Ward (1862), 31 Beav. 7.

Speech http://books.google.com/books?id=5jIwAAAAYAAJ&q=%22The+only+excuse+that+America+can+ever+have+for+the+assertion+of+her+physical+force+is+that+she+asserts+it+in+behalf+of+the+interests+of+humanity%22&pg=PA23#v=onepage to the Daughters of the American Revolution at Memorial Continental Hall in Washington, D.C. on April 17, 1916
1910s

The Great Infidels (1881)
Context: All the martyrs in the history of the world are not sufficient to establish the correctness of an opinion. Martyrdom, as a rule, establishes the sincerity of the martyr, — never the correctness of his thought. Things are true or false in themselves. Truth cannot be affected by opinions; it cannot be changed, established, or affected by martyrdom. An error cannot be believed sincerely enough to make it a truth.