Abraham Lincoln critiques slavery as a moral and social injustice rooted in human selfishness. He argues that the conflict between slavery and justice is irreconcilable, predicting that the expansion of slavery will lead to perpetual societal upheaval and moral conflict. Lincoln’s quote underscores his opposition to slavery on ethical grounds, advocating for justice and equality in society. It reflects his belief in the inherent contradiction between human rights and the institution of slavery, emphasizing the necessity of resolving this moral conflict.