“Firoz Tughlaq commanded his ‘fief-holders and officers to capture slaves whenever they were at war”. He had also instructed his Amils and Jagirdars to collect slave boys in place of revenue and tribute.”

The historian who witnessed this scene himself expresses his satisfaction by saying, “Behold the Sultan’s strict adherence to law and rectitude, how he would not deviate in the least from its decrees.”
Quoted from Goel, Sita Ram (2001). The story of Islamic imperialism in India. ISBN 9788185990231

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.

Lal, K. S. (1994). Muslim slave system in medieval India. New Delhi: Aditya Prakashan. Chapter 5 (quoting Masalik-ul-Absar, E.D., III, 580., Battutah)

Shams Siraj Afif, quoted in Lal, K. S. (1999). Theory and practice of Muslim state in India. New Delhi: Aditya Prakashan. Chapter 3

Shams Siraj Afif quoted in Lal, K. S. (1994). Muslim slave system in medieval India. New Delhi: Aditya Prakashan. Chapter 5

2000s, Intelligence Report: Rebels With A Cause (2000)

Source: The Culture of Make Believe (2003), p. 56

History of the Indies (1561)

1860s, Allow the humblest man an equal chance (1860)
Context: These natural and apparently adequate means all failing, what will convince them? This, and this only; cease to call slavery wrong, and join them in calling it right. And this must be done thoroughly — done in acts as well as in words. Silence will not be tolerated — we must place ourselves avowedly with them. Douglas's new sedition law must be enacted and enforced, suppressing all declarations that Slavery is wrong, whether made in politics, in presses, in pulpits, or in private. We must arrest and return their fugitive slaves with greedy pleasure. We must pull down our Free State Constitutions. The whole atmosphere must be disinfected of all taint of opposition to Slavery, before they will cease to believe that all their troubles proceed from us. So long as we call Slavery wrong, whenever a slave runs away they will overlook the obvious fact that he ran because he was oppressed, and declare he was stolen off. Whenever a master cuts his slaves with the lash, and they cry out under it, he will overlook the obvious fact that the negroes cry out because they are hurt, and insist that they were put up to it by some rascally abolitionist.