“My friends, I tell you that hitherto you have been prevented from even knowing what happiness really is, solely in consequence of the errors — gross errors — that have been combined with the fundamental notions of every religion that has hitherto been taught to men. And, in consequence, they have made man the most inconsistent, and the most miserable being in existence. By the errors of these systems he has been made a weak, imbecile animal; a furious bigot and fanatic or a miserable hypocrite; and should these qualities be carried, not only into the projected villages, but into Paradise itself, a Paradise would no longer be found!”

Pearls of Wisdom

Speech to the House of Commons, Jan 2009

Opera and Drama (1851)

Der Irrthum verhält sich gegen das Wahre wie der Schlaf gegen das Wachen. Ich habe bemerkt, daß man aus dem Irren sich wie erquickt wieder zu dem Wahren hinwende.
Maxim 331, trans. Stopp
Maxims and Reflections (1833)

Craig v. Harney, 331 U.S. 367, 392 (1947).
Judicial opinions

This has sometimes been paraphrased: "My failures have been errors of judgment, not of intent".
1870s, Eighth State of the Union Address (1876)
Context: I leave comparisons to history, claiming only that I have acted in every instance from a conscientious desire to do what was right, constitutional, within the law, and for the very best interests of the whole people. Failures have been errors of judgment, not of intent.

La science, mon garçon, est faite d’erreurs, mais d’erreurs qu’il est bon de commettre, car elles mènent peu à peu à la vérité.
Source: Journey to the Center of the Earth (1864), Ch. XXXI: Preparations for a voyage of discovery

Query XVII
1780s, Notes on the State of Virginia
Context: Difference of opinion is advantageous in religion. The several sects perform the office of a Censor morum over each other. Is uniformity attainable? Millions of innocent men, women, and children, since the introduction of Christianity, have been burnt, tortured, fined, imprisoned; yet we have not advanced one inch towards uniformity. What has been the effect of coercion? To make one half the world fools, and the other half hypocrites. To support roguery and error all over the earth. Let us reflect that it is inhabited by a thousand millions of people. That these profess probably a thousand different systems of religion. That ours is but one of that thousand. That if there be but one right, and ours that one, we should wish to see the 999 wandering sects gathered into the fold of truth. But against such a majority we cannot effect this by force. Reason and persuasion are the only practicable instruments. To make way for these, free enquiry must be indulged; and how can we wish others to indulge it while we refuse it ourselves?

Source: The House Of Commons At Work (1993), Chapter 9, The House of Commons Functions, p. 122