“Men have an all but incurable propensity to try to prejudge all the great questions which interest them by stamping their prejudices upon their language.”

Source: Dear Ijeawele, or A Feminist Manifesto in Fifteen Suggestions

Reason and Culture (1992)

Half-Truths and One-And-A-Half Truths (1976)

Douglass here quotes William Lloyd Garrison, who famously declared in the first issue of The Liberator: "I am in earnest — I will not equivocate — I will not excuse — I will not retreat a single inch — AND I WILL BE HEARD."
1850s, What to the Slave is the Fourth of July? (1852)
Context: I shall see, this day, and its popular characteristics, from the slave's point of view. Standing, there, identified with the American bondman, making his wrongs mine, I do not hesitate to declare, with all my soul, that the character and conduct of this nation never looked blacker to me than on this 4th of July! Whether we turn to the declarations of the past, or to the professions of the present, the conduct of the nation seems equally hideous and revolting. America is false to the past, false to the present, and solemnly binds herself to be false to the future. Standing with God and the crushed and bleeding slave on this occasion, I will, in the name of humanity which is outraged, in the name of liberty which is fettered, in the name of the constitution and the Bible, which are disregarded and trampled upon, dare to call in question and to denounce, with all the emphasis I can command, everything that serves to perpetuate slavery — the great sin and shame of America! "I will not equivocate; I will not excuse;" I will use the severest language I can command; and yet not one word shall escape me that any man, whose judgement is not blinded by prejudice, or who is not at heart a slaveholder, shall not confess to be right and just.

US Senator William Edgar Borah, writing in The Reader's Digest, Vol. 8, Issue 2 (1929), p. 776; this has only rarely begun to be attributed to Washington, since about 2010.
Misattributed

17 May 1937

Address to the United Nations (1963)
Context: On the question of racial discrimination, the Addis Ababa Conference taught, to those who will learn, this further lesson:
That until the philosophy which holds one race superior and another inferior is finally and permanently discredited and abandoned:
That until there are no longer first-class and second class citizens of any nation;
That until the colour of a man's skin is of no more significance than the colour of his eyes;
That until the basic human rights are equally guaranteed to all without regard to race;
That until that day, the dream of lasting peace and world citizenship and the rule of international morality will remain but a fleeting illusion, to be pursued but never attained;
And until the ignoble and unhappy regimes that hold our brothers in Angola, in Mozambique and in South Africa in subhuman bondage have been toppled and destroyed;
Until bigotry and prejudice and malicious and inhuman self-interest have been replaced by understanding and tolerance and good-will;
Until all Africans stand and speak as free beings, equal in the eyes of all men, as they are in the eyes of Heaven;
Until that day, the African continent will not know peace.