“Early impressions are hard to eradicate from the mind. When once wool has been dyed purple, who can restore it to its previous whiteness?”

Prof. Paul Brass, as quoted in Elst, K. On Modi Time : Merits And Flaws of Hindu Activism In Its Day Of Incumbency – 2015.

Enver Hoxha (1980) Eurocommunism is Anti-communism https://www.marxists.org/reference/archive/hoxha/works/euroco/env2-1.htm
Writings, Eurocommunism is Anti-Communism
Context: Nevertheless, Marxism-Leninism has not disappeared, it is living and flourishing as an ideology and a reality, materialized in the socialist social system constructed according to its teachings. Exemplifying this is socialist Albania, the Marxist-Leninist parties, and those millions and millions of workers and peasants who are fighting every day for the overthrow of the bourgeoisie, for democracy and national liberation. No force, no torture, no intrigue, no deception can eradicate Marxism-Leninism from the minds and hearts of men.

Letter to Abigail Adams (17 July 1775)
1770s
Source: Letters of John Adams, Addressed to His Wife

Statement made at Ebenezer Baptist Church (January 2007) http://www.washingtonpost.com/wp-dyn/content/article/2007/05/16/AR2007051600075.html.
2000s

Vol. VI, p 5, "First Talk in Rajahmundry (20 November 1949) http://www.jkrishnamurti.com/krishnamurti-teachings/view-text.php?tid=335&chid=4655&w=%22You+cannot+find+truth+through+anybody+else%22, J.Krishnamurti Online, JKO Serial No. 491120
Posthumous publications, The Collected Works
Context: You cannot find truth through anybody else. How can you? Surely, truth is not something static; it has no fixed abode; it is not an end, a goal. On the contrary, it is living, dynamic, alert, alive. How can it be an end? If truth is a fixed point, it is no longer truth; it is then a mere opinion. Sir, truth is the unknown, and a mind that is seeking truth will never find it. For mind is made up of the known; it is the result of the past, the outcome of time — which you can observe for yourself. Mind is the instrument of the known; hence it cannot find the unknown; it can only move from the known to the known. When the mind seeks truth, the truth it has read about in books, that "truth" is self-projected, for then the mind is merely in pursuit of the known, a more satisfactory known than the previous one. When the mind seeks truth, it is seeking its own self-projection, not truth. After all, an ideal is self-projected; it is fictitious, unreal. What is real is what is, not the opposite. But a mind that is seeking reality, seeking God, is seeking the known. When you think of God, your God is the projection of your own thought, the result of social influences. You can think only of the known; you cannot think of the unknown, you cannot concentrate on truth. The moment you think of the unknown, it is merely the self-projected known. So, God or truth cannot be thought about. If you think about it, it is not truth. Truth cannot be sought; it comes to you. You can go after only what is known. When the mind is not tortured by the known, by the effects of the known, then only can truth reveal itself. Truth is in every leaf, every tear; it is to be known from moment to moment. No one can lead you to truth; and if anyone leads you, it can only be to the known.

Source: Persistence of Memory