"This declared indifference, but, as I must think, covert real zeal for the spread of slavery, I cannot but hate. I hate it because of the monstrous injustice of slavery itself. I hate it because it deprives our republican example of its just influence in the world—enables the enemies of free institutions, with plausibility, to taunt us as hypocrites—causes the real friends of freedom to doubt our sincerity, and especially because it forces so many really good men amongst ourselves into an open war with the very fundamental principles of civil liberty—criticizing the Declaration of Independence, and insisting that there is no right principle of action but self-interest."
"[The authors of the Declaration of Independence] intended to include all men, but they did not mean to declare all men equal in all respects. They did not mean to say all men were equal in color, size, intellect, moral development or social capacity. They defined with tolerable distinctness in what they did consider all men created equal — equal in certain inalienable rights, among which are life, liberty, and the pursuit of happiness ... They meant to set up a standard maxim for free society which should be familiar to all: constantly looked to, constantly labored for, and even, though never perfectly attained, constantly approximated, and thereby constantly spreading and deepening its influence and augmenting the happiness and value of life to all people, of all colors, every where." (setting the stage for his changing ideas on slavery and equality to be "constantly approximated" or changing over time to come closer to the true ideal)
"That is the real issue. That is the issue that will continue in this country when these poor tongues of Judge Douglas and myself shall be silent. It is the eternal struggle between these two principles—right and wrong—throughout the world. They are the two principles that have stood face to face from the beginning of time; and will ever continue to struggle. The one is the common right of humanity and the other the divine right of kings. It is the same principle in whatever shape it develops itself. It is the same spirit that says, "You work and toil and earn bread, and I'll eat it." No matter in what shape it comes, whether from the mouth of a king who seeks to bestride the people of his own nation and live by the fruit of their labor, or from one race of men as an apology for enslaving another race, it is the same tyrannical principle."