“I am naturally anti-slavery. If slavery is not wrong, nothing is wrong. I can not remember when I did not so think, and feel. And yet I have never understood that the Presidency conferred upon me an unrestricted right to act officially upon this judgment and feeling. It was in the oath I took that I would, to the best of my ability, preserve, protect, and defend the Constitution of the United States. I could not take the office without taking the oath. Nor was it my view that I might take an oath to get power, and break the oath in using the power. I understood, too, that in ordinary civil administration this oath even forbade me to practically indulge my primary abstract judgment on the moral question of slavery. I had publicly declared this many times, and in many ways. And I aver that, to this day, I have done no official act in mere deference to my abstract judgment and feeling on slavery. I did understand however, that my oath to preserve the constitution to the best of my ability, imposed upon me the duty of preserving, by every indispensable means, that government — that nation — of which that constitution was the organic law.”

As quoted in His Brother's Blood: Speeches and Writings, 1838–64 https://books.google.com/books?id=qMEv8DNXVbIC&pg=PA198 (2004), edited by William Frederick Moore and Jane Ann Moore, pp. 198–199
1860s, Speech to the U.S. House of Representatives (April 1860)

1860s, "If Slavery Is Not Wrong, Nothing Is Wrong" (1864)
Context: Was it possible to lose the nation, and yet preserve the constitution? By general law life and limb must be protected; yet often a limb must be amputated to save a life; but a life is never wisely given to save a limb. I felt that measures, otherwise unconstitutional, might become lawful, by becoming indispensable to the preservation of the constitution, through the preservation of the nation. Right or wrong, I assumed this ground, and now avow it. I could not feel that, to the best of my ability, I had even tried to preserve the constitution, if, to save slavery, or any minor matter, I should permit the wreck of government, country, and Constitution all together.

As quoted in Sam Houston (2004), by James Haley, University of Oklahoma Press, pp. 390–91
1860s
Context: Fellow citizens, in the name of your rights and liberties, which I believe have been trampled upon, I refuse to take this oath. In the name of the nationality of Texas, which has been betrayed by the Convention, I refuse to take this oath. In the name of the Constitution of Texas, I refuse to take this oath. In the name of my own conscience and manhood, which this Convention would degrade by dragging me before it, to pander to the malice of my enemies, I refuse to take this oath. I deny the power of this Convention to speak for Texas.... I protest.... against all the acts and doings of this convention and I declare them null and void

Source: 1880s, Incidents and Anecdotes of the Civil War (1885), pp. 34– 35

Trump responding to a question https://www.youtube.com/watch?v=ZgImDKyPZwg about Jeff Sessions in a White House press briefing (25 July 2017)
2010s, 2017, July

Song lyrics, The Sensual World (1989)

Page 238
2000s, (2008)

Proceedings against the Dean of St. Asaph (1783), 21 How. St. Tr. 875.

Source: Dear John