My answer to this question is that one can recognize racial differences, such that races will not be equal in all respects, while also recognizing that all human beings are by their nature equal in their right to self-government, so that no one has the right to rule over others without their consent; and consequently one can condemn racism as a violation of that equal right to self-government. This is clearly stated by Lincoln, and it's implicit in Wade's book.
In his speech on the Dred Scott decision (June 26, 1857), Lincoln noted that Stephen Douglas, his opponent, was appealing to "a natural disgust in the minds of nearly all white people, to the idea of an indiscriminate amalgamation of the white and black races." He said that Douglas
"finds the Republicans insisting that the Declaration of Independence includes ALL men, black as well as white; and forthwith he boldly denies that it includes negroes at all, and proceeds to argue gravely that all who contend it does, do so only because they want to vote, and eat, and sleep, and marry with negroes! He will have it that they cannot be consistent else. Now I protest against that counterfeit logic which concludes that, because I do not want a black woman for a slave, I must necessarily want her for a wife. I need not have her for either, I can just leave her alone. In some respects she certainly is not my equal; but in her natural right to eat the bread she earns with her own hands without asking leave of any one else, she is my equal, and the equal of all others" (Speeches and Writings, Library of America, 1:397-98).He then went on to explain his interpretation of the principle of equality of rights in the Declaration of Independence:
"I think the authors of that notable instrument intended to include all men, but they did not intend to declare all men equal in all respects. They did not mean to say all were equal in color, size, intellect, moral developments, or social capacity. They defined with tolerable distinctness, in what respects they did consider all men created equal--equal in 'certain inalienable rights, among which are life, liberty, and the pursuit of happiness.' This they said, and this meant. They did not mean to assert the obvious untruth, that all were then actually enjoying that equality, nor yet, that they were about to confer it immediately upon them. In fact they had no power to confer such a boon. They meant to set up a standard maxim for free society, which should be familiar to all, and revered by 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 everywhere" (1:398).In his speech on the Kansas-Nebraska Act (October 16, 1854), Lincoln insisted that "the poor negro has some natural right to himself," and thus he has a natural right to self-government rooted in the human nature of self-ownership. "My faith in the proposition that each man should do precisely as he pleases with all which is exclusively his own, lies at the foundation of the sense of justice there is in me." He denied Douglas's claim that the right of self government gave people in the western territories of the United States the right to vote for becoming slave states.
"The doctrine of self government is right--absolutely and eternally right--but it has no just application, as here attempted. Or perhaps I should rather say that whether it has such just application depends upon whether a negro is not or is a man. If he is not a man, why in that case, he who is a man may, as a matter of self government, do just as he pleases with him. But if the negro is a man, is it not to that extent, a total destruction of self-government, to say that he too shall not govern himself? When the white man governs himself, that is self-government; but when he governs himself, and also governs another man, that is more than self-government--that is despotism. If the negro is a man, why then my ancient faith teaches me that 'all men are created equal;' and that there can be no moral right in connection with one man's making a slave of another" (1:328).He concluded that the principle of self-government is grounded in the idea that "no man is good enough to govern another man, without that other's consent."
So while Lincoln recognized that human beings are naturally unequal in many respects, including racial differences, he also saw that they are equal in those minimal emotional and intellectual capacities that sustain a moral sense and thus identify them as members of the human species. This understanding of human equality requires not equality as identity but equality as reciprocity: although unequal in many ways, all normal human beings will resist exploitation, will claim ownership in themselves and their property, and will demand social cooperation based on mutual consent to reciprocal exchange.
He argued: "This is a world of compensation; and he who would be no slave, must consent to have no slave" (2:19). "As I would not be a slave, so I would not be a master" (1:484). Thus did Lincoln capture the logic of equality supporting republican government. Human beings are unequal in many respects. But our natural resistance to exploitation is such that no normal person would consent to be a slave, and so no one can consistently seek mastery based on any principle of superiority without exposing himself to being enslaved against his will. Lincoln reasoned:
"If A can prove, however conclusively, that he may, of right, enslave B--why may not B snatch the same argument, and prove equally, that he may enslave A?--
"You say A is white, and B is black. It is color, then; the lighter, having the right to enslave the darker? Take care. By this rule, you are to be slave to the first man you meet, with a fairer skin than your own.
"You do not mean color exactly?--You mean the whites are intellectually the superiors of the blacks, and, therefore have the right to enslave them? Take care again. By this rule, you are to be slave to the first man you meet, with an intellect superior to your own.
"But, say you, it is a question of interest; and, if you can make it your interest, you have the right to enslave another. Very well. And if he can make it his interest, he has the right to enslave you" (1:303).As I have argued in some previous posts, there is a Darwinian logic against slavery and for the classical liberal principle of equal liberty that runs through Lincoln's reasoning as well as Charles Darwin's own opposition to slavery. Slavery is a form of social parasitism, and human beings are naturally evolved to detect and resist parasitic exploitation. As Daron Acemoglu and James Robinson (in Why Nations Fail) have argued, slavery was an integral part of the "extractive institutions" by which elites have exploited those under their rule, and it was the aim of liberal thought to replace such bad institutions with the good "inclusive institutions" that are responsible for the prosperity and liberty of the modern world. (What they call "inclusive institutions" corresponds closely to what Douglass North, John Wallis, and Barry Weingast would call "open access societies," which was the subject of a previous post.)
Although he doesn't elaborate the point as clearly as Lincoln, Wade does at least implicitly embrace this same Darwinian logic for equal liberty and against racist exploitation.
At the beginning of his book, however, Wade tries to evade the moral and political implications of his scientific reasoning about racial evolution in human history. He does this by invoking the is/ought dichotomy. He claims: "Racism and discrimination are wrong as a matter of principle, not of science. Science is about what is, not what ought to be. Its shifting sands do not support values, so it is foolish to place them there" (7). If that were true, then morality and politics would belong to a normative realm of moral values that transcends the empirical realm of natural facts studied by science. But is this really true? If science were to discover that some races were genetically adapted for slavery, so that they were naturally inclined to serve their masters and never to resist their exploitation, wouldn't this provide empirical evidence that the enslavement of such races is right?
In fact, some of the proponents of slavery in the nineteenth century argued that the African race was biologically adapted for slavery, and that this race was actually a separate species. One of the main motivations for Darwin's writing of The Descent of Man was to refute this claim. He recognized the many differences--both physical and mental--between the races, and yet he saw the fundamental similarity--including the moral sense--that showed that all the races belonged to one human species.
Wade agrees with this. "Human nature is essentially the same worldwide" (244). While racial science shows that some races have "relative advantages in some traits" in some environments over other races, there is no evidence that any race is "superior in any absolute sense," which is "the essence of racism" (8, 250). "The central premise of racism, which distinguishes it from ethnic prejudice, is the notion of an ordered hierarchy of races in which some are superior to others. The superior race is assumed to enjoy the right to rule others because of its inherent qualities" (17). This premise is false. "People being so similar, no one has the right or reason to assert superiority over a person of different race" (9).
Notice how Wade here violates his fact/value dichotomy. The fact of people being similar supports the value condemning racism. Notice also the implicit logic of Darwinian liberalism that allows for the free expression of individual and racial differences, while denying that anyone claiming racial superiority has the right to rule others without their consent.
Wade's Darwinian liberalism becomes clear in his endorsement of the argument of Acemoglu and Robinson on the need to move from "extractive institutions" to "inclusive institutions" (Wade, 148-49, 175, 180, 193-96). Inclusive institutions are more innovative, more productive, more peaceful, and therefore better institutions, because they are based on the liberal principle that the right of self-government belongs equally to all human beings.
As Wade indicates, the move to inclusive liberal institutions must overcome tribalism, which is the instinctive xenophobic propensity to favor one's own group over others. Racism is an expression of such tribalism, in favoring one's race over others. Here one can see clearly why Wade's argument is not racist: at the core of his argument is his claim that the tribalism of racial ethnocentrism belongs to an ancient stage of human evolution that has to be overcome to move into modern states and inclusive institutions (see 136, 173-82, 196-97).
Lincoln saw racial tribalism as the deepest obstacle to achieving "perfect social and political equality." The disgust elicited by racial intermarriage was one powerful expression of such tribalist bigotry. Eliminating such bigotry might require promoting racial intermarriage so that racial differences would eventually disappear. It is altogether fitting and proper, therefore, that on the bicentennial of Lincoln's birth in 2009, President Barack Obama spoke at the Abraham Lincoln Library in Springfield, Illinois.
Wade indicates that if human racial differentiation were to continue at the same rate as it has for the past 50,000 years, the human races at some time in the future could become separate species. But this is unlikely to happen in modern inclusive societies, because "the forces of differentiation seem now to have reversed course due to increased migration, travel, and intermarriage" (71). For example, African Americans share a high proportion of their genomes with Europeans (101). The final triumph of inclusive institutions might be ever extensive racial intermarriage so that racial differences would disappear, and consequently racial tribalism would be extinguished.
Some of these points are elaborated in other posts here, here, here, here, here, here, and here.