“And so, the idea of slave property contradicts the idea of private property, and the Southerners taking their stand on their property rights and their slaves were, in fact, taking their stand on a principle which was incompatible with the idea of constitutional government.”

Source: Democracy: The God That Failed (2001), P.217

1860s, Cooper Union speech (1860)

Source: Economic and Philosophic Manuscripts of 1844, p. 99, The Marx-Engels Reader

"The Foundations of Historical Materialism," Studies in Critical Philosophy (1972), p. 32

As quoted in His Brother&#x27;s Blood: Speeches and Writings, 1838&amp;ndash;64 https://books.google.com/books?id=qMEv8DNXVbIC&amp;pg=PA199 (2004), edited by William Frederick Moore and Jane Ann Moore, p. 199 <br class="br">1860s, Speech to the U.S. House of Representatives (April 1860)

2000s, The Real Abraham Lincoln: A Debate (2002), Q&A

Regarding using the words &quot;slave&quot; or &quot;slavery&quot; within the U.S. Constitution, in Madison&#x27;s notes (25 August 1787)<br>Variants:<br>Madison, in convention, when an attempt was made to introduce the term slave into the Constitution, said: &quot;It must not be so; because we intend this Constitution to be the great charter of human liberty to the unborn millions who shall enjoy its protection, and who should never see that such an institution as slavery has ever known in our midst.&quot;<br>As paraphrased or quoted in Our National Condition, and Its Remedy : A Sermon, Preached in the Pine Street Church, Boston, on Sunday, June 22, 1856 (1856) https://archive.org/details/ournationalcondi00dext by Henry Martyn Dexter<br>Madison said he &quot;thought it wrong to admit in the Constitution the idea that there could be property in man. We intend this Constitution to be the great charter of human liberty to the unborn millions who may enjoy its protection, and who shall never see that such an institution was ever known in their midst.<br>As paraphrased or quoted in Reminiscences of James A. Hamilton: Or, Men and Events, at Home and Abroad (1869), Appendix D, Property in Man, p. 625 https://books.google.com/books?id=0uQEAAAAYAAJ&amp;pg=PA625#v=twopage&amp;q&amp;f=false <br class="br">1780s, The Debates in the Federal Convention (1787) <br class="br">Context: Mr. MADISON thought it wrong to admit in the Constitution the idea that there could be property in men. The reason of duties did not hold, as slaves are not like merchandize, consumed, &amp;c

A Human Being Cannot Be Justly Owned (1835)
Context: The slave-holder claims the slave as his Property. The very idea of a slave is, that he belongs to another, that he is bound to live and labor for another, to be another’s instrument, and to make another’s will his habitual law, however adverse to his own. Another owns him, and, of course, has a right to his time and strength, a right to the fruits of his labor, a right to task him without his consent, and to determine the kind and duration of his toil, a right to confine him to any bounds, a right to extort the required work by stripes, a right, in a word, to use him as a tool, without contract, against his will, and in denial of his right to dispose of himself, or to use his power for his own good. “A slave,” says the Louisiana code, “is in the power of the master to whom he belongs. The master may sell him, dispose of his person, his industry, his labor; he can do nothing, possess nothing, nor acquire any thing, but which must belong to his master.” “Slaves shall be deemed, taken, reputed, and adjudged,” say the South-Carolina laws, “to be chattels personal in the hands of their masters, and possessions to all intents and purposes whatsoever.” Such is slavery, a claim to man as property. Now this claim of property in a human being is altogether false, groundless. No such right of man in man can exist. A human being cannot be justly owned. To hold and treat him as property is to inflict a great wrong, to incur the guilt of oppression.

Source: Epistulae Morales ad Lucilium (Moral Letters to Lucilius), Letter XII: On old age, Line 11.