“If there is a sentence in the creed which we cannot say together, there is nothing in Christ which we would wish to be different; and heresies of the heart are quite as dangerous, and to me as estranging, as errors in the head.”

95
The Chidakasha Gita (1927)

Source: The Sociology of Secrecy and of Secret Societies (1906), p. 444

The Two Paths, Lecture II: The Unity of Art, section 54 (1859).

Letter to D. Balfour.
Others

Letter to John Randolph (1 December 1803), 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. 109 http://files.libertyfund.org/files/806/0054-10_Bk.pdf, pp. 54
1800s, First Presidential Administration (1801–1805)

First Journal of Travel (1840)

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 158.

Recantation (22 June 1633) as quoted in The Crime of Galileo (1955) by Giorgio de Santillana, p. 312 http://law2.umkc.edu/faculty/projects/ftrials/galileo/recantation.html. <!-- also in Galileo's Mistake (2012) by Wade Rowland -->
Other quotes
Context: After an injunction had been judicially intimated to me by this Holy Office, to the effect that I must altogether abandon the false opinion that the sun is the center of the world and immovable, and that the earth is not the center of the world, and moves, and that I must not hold, defend, or teach in any way whatsoever, verbally or in writing, the said false doctrine, and after it had been notified to me that the said doctrine was contrary to Holy Scripture — I wrote and printed a book in which I discuss this new doctrine already condemned, and adduce arguments of great cogency in its favor, without presenting any solution of these, and for this reason I have been pronounced by the Holy Office to be vehemently suspected of heresy, that is to say, of having held and believed that the Sun is the center of the world and immovable, and that the earth is not the center and moves:
Therefore, desiring to remove from the minds of your Eminences, and of all faithful Christians, this vehement suspicion, justly conceived against me, with sincere heart and unfeigned faith I abjure, curse, and detest the aforesaid errors and heresies, and generally every other error, heresy, and sect whatsoever contrary to the said Holy Church, and I swear that in the future I will never again say or assert, verbally or in writing, anything that might furnish occasion for a similar suspicion regarding me; but that should I know any heretic, or person suspected of heresy, I will denounce him to this Holy Office, or to the Inquisitor or Ordinary of the place where I may be. Further, I swear and promise to fulfill and observe in their integrity all penances that have been, or that shall be, imposed upon me by this Holy Office. And, in the event of my contravening, (which God forbid) any of these my promises and oaths, I submit myself to all the pains and penalties imposed and promulgated in the sacred canons and other constitutions, general and particular, against such delinquents. So help me God, and these His Holy Gospels, which I touch with my hands.
I, the said Galileo Galilei, have abjured, sworn, promised, and bound myself as above; and in witness of the truth thereof I have with my own hand subscribed the present document of my abjuration, and recited it word for word at Rome, in the Convent of Minerva, this twenty-second day of June, 1633.