Pro-life activists and thinkers often remark on what they regard as the philosophical and constitutional linkages between America’s abortion regime and slavery. Justin Dyer’s important new book, Slavery Abortion, and the Politics of Constitutional Meaning, takes these claims seriously. Abortion and slavery, Dyer finds, “have a historical, philosophical, and legal nexus in America” (p. xii).

The success of abortion rights depended on the denial of this nexus. Defenders of Roe v. Wade, Dyer observes, “spun deliberately false narratives” (p. 124) since it was in their interest to show that abortion liberties were deeply rooted in the American rights tradition. Thus, they argued that the state anti-abortion laws, which had been on the books since the nineteenth century, were passed primarily out of concern for women’s health.

Dyer, however, finds much evidence that state lawmakers were deeply concerned about fetal life. “At least seventeen state codes in the nineteenth century,” Dyer notes, called abortion “‘manslaughter,’ ‘murder,’ or ‘assault with intent to murder’” (p. 116). Yes, it is true, Dyer acknowledges, that abortion was once tolerated prior to quickening. But Roe’s defenders are wrong to offer this historical fact as evidence that abortion was a protected common-law liberty with deep roots in American and British history. Such early abortions were only tolerated, Dyer argues, because of the limits of scientific understanding. “In the absence of modern technology,” Dyer finds, “quickening . . . was often the best available evidence of new life (and thus the starting point for any criminal prosecution)” (p. 114). When science improved in the nineteenth century, doctors sought to eliminate the old, arbitrary distinction by advocating laws that protected human life from the moment of conception. “The anti-abortion legislation in the mid-nineteenth century,” Dyer concludes, “was not so much an aberration, but a development” (p. 115). Therefore, Roe represented “a radical break from America’s history and traditions” (p. 127) and depended on a historical narrative that was “largely false” (p. 128).

What does this have to do with slavery? Dyer contends that anti-abortion laws and the Fourteenth Amendment were informed by the same natural law tradition, which embraced the dogma that all human beings are equal. As Dyer contends, “it was the natural law tradition . . . that provided the intellectual scaffolding for both the Fourteenth Amendment and state anti-abortion laws” (p. xii). Thus, legislators in the Ohio legislature “who voted to approve [an anti-abortion] bill and ratify the Fourteenth Amendment in the same legislative session apparently saw no contradiction between the two” (p. 112). They were, in fact, affirming the equality of human beings in both cases.

The philosophical and historical irony is that the Fourteenth Amendment was used a century later to justify a sweeping constitutional right to abortion. But the justices in Roe, Dyer contends, could only do so by refusing to attribute any moral significance to the fact that embryos and fetuses are living human organisms. “At a minimum,” Dyer tells us, “the logic of Justice Blackman’s [majority] opinion seemed to regard human status as irrelevant to the question of who may claim rights under the Constitution” (p.79). And, in fact, Roe seemed to go further still by calling embryos and fetuses merely “potential life,” as if they were not living human organisms (p. 152).

The denial of fetal personhood was necessary to ground abortion rights on the guarantees of the Fourteenth Amendment. “For if human beings at every stage of development had been recognized as rights-bearers in some fundamental moral sense,” Dyer observes, “then it would have strained credulity to insist that the Fourteenth Amendment, written to secure the fundamental rights of human nature to all persons, prohibited states from protecting one class of human beings from the private use of lethal force” (pp. 69-70).

Nonetheless the fact that embryos and fetuses, like slaves before them, are living beings creates problems for the very justices who regard them as mere property. Testimony in the partial-birth abortion cases, Dyer reminds us, made it difficult to deny that “bones were breaking” (p. 102). Such sobering doses of reality left euphemisms like “potential life” difficult to maintain (p. 101). In those cases justices were left to decide whether the right to the private use of force against fetuses was absolute. In a similar way, Dyer argues that the humanity of slaves forced justices to confront a similar question. “Did a legal right to the services of slaves,” justices once asked, “also imply a right to use whatever means necessary to force the slave to render those services?” (p. 99). “As it became more and more difficult to sustain Blackmun’s facile assertion that it is merely ‘potential’ life at stake in these surgeries,” Dyer observes, “it has become therefore necessary to defend what honest observers can only describe as killing” (p. 98). And this violence, he concludes, “cannot ultimately be reconciled with American liberalism.” The result, Dyer’s believes, is a “Constitutional disharmony” between America’s deeper principles and Constitutional law.

Dyer might have reflected more deeply on the possible discontinuities between slavery and abortion. Abortion, for example, is the only controversy in American history that has pitted activists against one another who sincerely believe they are defending basic human rights.

Perhaps Dyer would grant that pro-choice activists, unlike slaveholders, are driven by egalitarian ideals. Even so, his view seems to be that pro-choice activists have strayed from the American liberal tradition by abandoning “the moral principle that human beings have certain rights simply by virtue of their humanity” (p. 151). To be sure, many pro-choice thinkers have embraced competing egalitarian principles. Peter Singer, for example, argues that equality should depend not on membership in the human species, but on possessing the requisite psychological traits to have interests, especially sentience and self-awareness. His arguments have enjoyed even greater influence in the animal rights movement, which blames barbarism against animals on the very egalitarian principles that Dyer celebrates. Such philosophical ruptures in the liberal tradition have led to reasonable disagreements over how to understand and apply the principle of equality. This reality, moreover, makes today’s moral battles over personhood quite different from the struggle over slavery.

But how does someone like Dyer advocate for his favored egalitarian principle? Dyer, after all, acknowledges that the past acceptance of his conception of egalitarianism rested on “dogmas” that “could not be logically or rationally demonstrated” (p. 151). Dyer does not address this question directly. Instead, he gently reminds us that a common understanding of egalitarianism animated the campaigns against slavery and abortion. And if this is right, how can we celebrate the principles of the abolitionists, but not those of the right-to-lifers?

Perhaps Dyer’s pro-choice critics will answer that abolitionists were right to conclude that slavery is immoral, but they based it on the mistaken notion that humans are inherently valuable. They might even grant that this older liberalism, informed as it was by the Christian belief that humans alone were made in the image and likeness of God, worked well enough in the struggles against slavery and segregation. The post-civil rights contests for reproductive freedom and animal liberation, such critics might add, highlight the limits and contestability of the old liberalism.

A brief review cannot do justice to a work as nuanced, original, and provocative as Slavery, Abortion, and the Politics of Constitutional Meaning. I hope it enjoys the wide, contentious, and fair-minded hearing that it deserves.