Lincoln believed that the institution of slavery was morally wrong; and evil; that it was inhumane and monstrous. He said that if slavery is not wrong, then nothing is wrong. He said that a house divided cannot stand, and the Union cannot endure permanently half slave and half free. He said that slavery absolutely could not be permitted to spread into the West. He said that slavery must be placed in the course of ultimate extinction. In December 1862 he revealed what he meant by "ultimate": basically gradual emancipation, with compensation, over 37 years, from 1863 to 1900. He said that to rob a man of the fruits of his labor is tyranny.

However Lincoln also recognized the prejudice of much of the white population of the US, and shared some of it. He believed that blacks and whites were fundamentally different. He believed that blacks probably were intellectually inferior to whites. He believed that it would be better and more desirable if America was a homogeneous, pure white society. He doubted that blacks could be assimilated into the dominant white culture. He did not advocate that blacks should be able to vote or serve on juries or hold office or intermarry with whites. At one point in early 1865 he did suggest that Afro-Americans who had served in the war and who were educated or owned property should be able to vote, but he dropped the matter as soon as objections were raised. He concluded it would be best to leave the matter to the states. He did not advocate equality for Afro-Americans, as a whole, beyond the end of slavery. People of that time period assumed a kind of Darwinian struggle for power, the law of the jungle, survival of the fittest, the big fish eat the little fish. They did not see peaceful coexistence as equals as a realistic possibility. Therefore Lincoln believed that one race must dominate the other, and so preferred that whites should dominate blacks rather than blacks should dominate whites. Lincoln seems to have felt that there really was no place for black people in America after they ceased to be slaves. His vision was an ethnocentric vision, a narrow and limited vision, of a pure white society. Because Lincoln believed in the racial superiority of whites relative to nonwhites, historians such as Lerone Bennett characterize him as a bigot or racist or white supremacist.

However Lincoln also had a humanitarian side. This side opposed slavery and wanted to end it, in a way that would not disrupt the white South. Lincoln did not seek to harm black people. Instead, he did not want them to continue to be subjected to abuse and mistreatment and degradation and exploitation. It is as if he felt that the white majority that held power was hopelessly prejudiced, and this was permanent, and it would never change. It was as if he recognized that many members of the prejudiced white majority behaved like wolves, and the blacks were sheep. It was as if many whites were predators and blacks were the prey. Perhaps Lincoln felt that the wolf will never stop being a wolf; and the only way to protect the sheep from the wolves is to separate the sheep from the wolves. In this sense Lincoln was a humanitarian. He was trying to do what he thought was best for white people (racially homogeneous pure white society) and what was also best for black Americans (end slavery and move them away from the wolves). Lincoln may have felt that if blacks had a country of their own, somewhere else, they could run it, control it, govern themselves, have power over their own lives.

From the black "side of the fence", Elijah Muhammad and Marcus Garvey shared some of the same ideas (minus the belief in the superiority of Europeans and Euro-Americans).

It could be argued that Lincoln was a racist humanitarian, as contradictory as that seems. Most of all, he was a pessimist. And his pessimistic assumptions and premises led him to pessimistic conclusions.