Repeal the Missouri Compromise - repeal all compromises - repeal the Declaration of Independence - repeal all past history, you still cannot repeal human nature. It will be the abundance of man's heart that slavery extension is wrong; and out of the abundance of his heart, his mouth will continue to speak.

The quote by Abraham Lincoln highlights his belief that slavery was fundamentally incompatible with human nature and moral truth. By rhetorically suggesting that one could “repeal the Missouri Compromise… repeal the Declaration of Independence… repeal all past history,” Lincoln stresses that no law, political maneuver, or historical revision could erase the moral reality that slavery extension is wrong. In his view, justice and conscience are not dependent on legislation but are deeply rooted in the human heart.

Lincoln’s reference to the “abundance of man’s heart” underscores his conviction that moral truths eventually prevail, no matter how much politicians may try to suppress them. He believed that the widespread human recognition of slavery’s injustice would continually resurface in public discourse, even if governments or compromises attempted to silence it. This reflects his faith in the moral conscience of the people as stronger than temporary political arrangements.

The deeper meaning of this quote lies in Lincoln’s rejection of purely political solutions that sought to appease both North and South through compromise. He argued that compromises could not override the moral law or the natural rights enshrined in the Declaration of Independence. To him, slavery was not simply a political issue but a profound moral wrong, and human nature itself would rebel against its expansion.

The origin of this quote is from Lincoln’s Peoria speech in 1854, delivered in response to the Kansas-Nebraska Act, which effectively repealed the Missouri Compromise by allowing new territories to decide on slavery through popular sovereignty. This speech marked a turning point in Lincoln’s political career, showcasing his eloquence and moral clarity. The quote captures his central message: that slavery, regardless of legal manipulation, stands condemned by history, human nature, and the moral conscience of mankind.