Many of us are committed to basic equality (BE). We believe that all human beings are owed equal respect and concern no matter their race, gender, sexual orientation, economic position, or the extent of their physical and psychological abilities. Not everyone holds this commitment, but a large majority does, and those who do not are often reluctant to openly deny it. This is a remarkable historical fact. It has not always been this way. It is also a fragile phenomenon. The hegemony of BE could dissolve. In his powerful book, Basic Equality, Paul Sagar takes significant steps to understand this predicament. He offers a characterization of the commitment to BE, an explanation of its widespread incidence and its contingency, and a justification of it as a normative principle.

The content of the commitment to BE is relatively vague. This is so because it is not always clear what the metric is in which all people are held to be equal (whether it concerns their status, worth, or authority, for example). It is also not obvious how the commitment relates to more specific claims (what equal civil, political, economic, cultural, and other rights people are supposed to have). This commitment to equality is not empty, however, as it sets negative constraints on any specific account of social justice. It prohibits some people from using superior power to dominate and oppress others, treating them as fundamentally less deserving of respect and concern because of specific features such as their race, gender, sexual orientation, or abilities.

How did this commitment arise? Sagar’s proposed explanation draws on two core points, one psychological and the other historical. The first point builds on the fact that, quite generally, “human beings are psychological essentialists” (62). By this, he means that they have a disposition to understand the world as sharply divided into types of beings. This disposition structures specific inquiries and views in natural and social science rather than being an output of them. In the case of our understanding of the human domain, the disposition can have problematic and evil developments. This tendency has been harnessed to rationalize the domination and oppression of some groups by portraying their members as lesser instances of the human kind. At the limit, it leads to dehumanization and facilitates their elimination or their systematic subjugation (as is evident in genocides, slavery, and colonialism).

However, our tendency toward psychological essentialism can also result in benign expressions. A crucial instance is the idea that there is a human essence shared by every individual of the human set. This idea is at the core of BE. However, to fully understand it, we also have to appreciate that humanist essentialism has emerged and spread in specific historical contexts. In the West, on which Sagar’s book focuses, an important antecedent is the Christian idea that all human beings are made in the image of God and are loved by God. A secularized version of this idea developed in modern times and became hegemonic after World War 2 when roughly liberal democratic societies sought to portray their advantages in competition with fascism and communism (alleging that the former denied BE and that the latter did not really honor BE, even though it paid lip service to it). The book also notes the accumulated impact of social and political movements defending the claims of oppressed groups such as workers, women, colonized peoples, and LGBTQ folks. The historical upshot, Sagar argues, is that the political processes in which we manage our various conflicts and disagreements must be consistent with the acceptance of BE.

But is the commitment to BE normatively sound? Should we really think that we are each other’s equals? What is the normative justification of the commitment to BE? In the last few decades, moral and political philosophers have attempted to provide what Sagar calls “foundationalist” arguments for BE. These, roughly, consist of trying to show that human beings share certain features, and that the fact that they have them gives us reason for thinking that their carriers matter—and matter equally. Sagar surveys these foundationalist arguments and concludes that they fail. For example, they have tended to be exclusionary (as features alleged to be crucial, like rationality, are not held at all, or are not held to the required degree, by some human individuals). Or they are incapable of justifying the positive and distinctive moral standing of human beings (as it is not clear that some of the features mentioned are morally significant, and some others which are, like sentience, are also shared by nonhuman animals).

Sagar, in turn, proposes a different justificatory strategy. We can understand a reference to a human essence in terms of a “double fiction” (p. 113)—there is in fact no human essence, but we act as if there was one, and it is the only decisive factor in questions of assigning fundamental worth and value. We “immerse” ourselves, through various cultural practices, into that fiction and invoke it to defend inclusive moral and political arrangements. How could this make sense? Sagar says that we have compelling reasons to embrace BE, and the fictional picture it relies on because by doing so we effectively serve our goals of reducing cruelty and injustice. There is less cruelty and injustice in societies whose people are immersed in this humanist fiction than in those in which they are not. Treating each other as basic equals is thus a good thing for us. This view, Sagar argues, is not debunked by awareness of the fact that it rests on fiction. The commitment to BE can be stable under reflection once we understand how it arises and our compelling practical reasons for maintaining it. The fiction involved, therefore, is not a deception used by some powerful agents to subjugate and take advantage of others (in fact it helps undermine operations of that kind). This vindication of our commitment to BE will not convince someone who asks for a “foundationalist” justification of it, but in Sagar’s view that approach leads to a blind alley anyway. It also will not convince a hardcore bigot who rejects BE and is not troubled by cruelty and injustice. The justificatory task, as Sagar pursues it, is concentrated on reassuring those who are committed to BE that they are on the right track.

Sagar’s book is wonderfully written, wide-ranging, and original. It will reward close reading by philosophers and social scientists interested in understanding the idea of basic equality. The book’s proposed psychological and historical explanatory strategy is, I think, particularly powerful. However, I find the proposed normative justification of BE less compelling. It rests on an endorsement of ethical subjectivism and relativism (see e.g. pp. 48–50, 52, 54, 58–59, 133–136, 145, 163). According to this approach, roughly, certain acts or norms are right if and only if, and because, they are aligned with the guiding attitudes of the agents endorsing them. We should hold BE to be true if our commitment to it reflects our core values and aspirations.

Unfortunately, the book ignores standard objections to relativism in moral philosophy. One such objection is that it leads to contradiction. If a group, consistently with their deepest values and aspirations, approves of p (e.g. that people ought to treat each other as basic equals), and another approves of not-p, then both p and not-p would be true. This result might be avoided by indexing truth claims to the perspectives of those affirming them. But the second common objection then says that relativism fails to make sense of moral disagreement. When you and I disagree about the truth of p, what is going on is not just that p is true according to me and p is false according to you. In addition, you think that I am mistaken to believe that p, however consistently I endorse it given my values and aspirations. Intuitively, it is strange to say that we are equals just because we treat each other as such, and that “[i]f we collectively stop viewing and treating each other as basic equals, then we will stop being basic equals” (p. 174). This view fails to make full contact with the seriousness of the commitment to BE.

Many of us would say that people are basic equals even if some (or all) fail to view and treat them as such. We do not take BE to be something we create with our attitudes, but something our attitudes should reflect. These remarks line up with objectivist views in metaethics. There is underway a revival of them in moral philosophy (e.g. in recent work by Russ Shafer-Landau, Derek Parfit, and David Enoch). An objectivist approach would also motivate further exploration of what Sagar calls the “foundationalist” strategy of defense of BE. It is hasty to think that it leads to a dead end. Work on it has started quite recently and could still bear fruits. However, the debate must continue, and Sagar’s book is an important contribution to it.