Imagine that a minority of humans has been enslaved to serve the majority. Suppose this minority consists exclusively of individuals in the bottom third of the population for general intelligence and other psychological capacities that may substantially determine the absolute level of well-being one can attain. Due to their subjugation, members of this minority fall woefully short of their full potential for well-being. Still, their loss is more than offset by the gain in well-being that accrues to the top two-thirds of the population, whose capacity for well-being is, after all, greater than that of the bottom-third. In fact, even if freeing the minority increased each of its members’ well-being to an absolute peak, their gain would be more than offset by the loss of well-being to the majority, who now must allot more resources to the minority, in addition to doing more work for themselves. Thus, given a choice between (a) enslaving the minority and (b) not enslaving the minority, we choose (a) to maximize collective well-being, but we choose (b) to minimize inequality in well-being. On option (b), members of the minority get closer to their absolute peak, while members of the majority get further from theirs. Equality of well-being isn’t achieved, nor is it strictly required. But inequality is reasonably reduced.
When our overriding goal is to maximize collective well-being, individual liberty can in principle be granted or, we can also say, distributed based solely on well-being. Differences in capacity for well-being, along with moral indifference to anything other than maximizing collective well-being, together can lead to the denial of certain individuals’ basic rights. This approach to denying rights may sound familiar. Non-human animal rights appear to be denied (or else sharply restricted) on the presumption that non-human animals cannot attain human levels of well-being, and that sacrificing non-human animals’ well-being for the benefit of humans helps maximize collective well-being. Given that Sam makes all conscious creatures members of the moral community, and given that all such beings, as products of evolution, exist on a continuum in nature, we can ask: What stops us from denying rights to certain humans on the same basis we deny rights to non-human animals? 1
If the answer is “humans’ psychological capacities, however their limits vary by individual, warrant possession of basic rights, but non-human animals’ psychological capacities do not,” then we can ask: What morally relevant distinction between these two sets of capacities justifies basic rights for humans but not for non-human animals? Unless we deny that increases and decreases in well-being are all that matter morally, the only answer can be “the amount of well-being those capacities support.” And this answer appears to make the enslavement scenario morally permissible in principle (however unlikely its occurrence).