Human dignity: All froth about it, but few discuss it with precision and nuance. That’s what Princeton political philosopher George Kateb sets out to do in this powerful and ambitious book. He provides a sterling example of one of the most challenging of genres, the philosophic essay. He writes not just for other scholars but for anyone who loves to think. I won’t mislead you by pretending that Human Dignity is easy and pleasant. It is demanding and pleasant, the pleasures being those of an argument that illuminates an important subject.

Where won’t the consideration of human dignity lead us? What other major question about our species fails to touch it or to be touched by it? We can’t define it without grasping what it means to be human, both in common with and in contradistinction to what it means to belong to other species. Kateb distinguishes between two aspects of human dignity: our (equal and infinite) dignity as individuals and our (superior and infinite) dignity as a species. Human dignity is both the “status of the individual” and the “stature of the human species.” (In his final chapter, Kateb also considers the stature of outstanding individuals, and defends the equal status or dignity of all against the threat that this stature might seem to pose.)

Individual dignity demands proper recognition and respect, to be achieved by a system of human rights. Kateb discusses at some length the human attributes thus deserving of respect, and enumerates the rights that these imply. As always, he here expresses his profound wariness of statism: Human dignity rebuts not only oppression, but paternalism. While no one is suffering or even discontented in the dystopia of Brave New World, he says, it represents a massive assault on dignity. In the real world, he prefers the more individualist American model of rights and constitutionalism to the more statist European one.

Sure, there are differences between Europe and America, but President Barack Obama would happily reduce them. On both continents, the political reality of “equal dignity” is ever-bigger bureaucracies (national and transnational) catering to ever more compliant clients. Fainter souls than Kateb might doubt whether dignity is still of use in our domestic discourse today.

Readers who deem themselves environmentally progressive may bristle at the “speciesism” of Kateb’s affirmation of the unique stature of humanity. His argument is that we are unique in being the “partly natural” species, the only one whose conduct cannot be predicted on the basis of its genetic endowment. As the only creature that is partly what it makes of itself rather than what nature has made of it, whose future (both as individuals and a species) is therefore open as no other creature’s can be, humanity is uniquely dignified.

Yet Kateb proves that he too can hug trees (if only on a higher plane of argument). For it attends the superior dignity of our species that we alone are capable of conceiving the plan of serving as the steward of nature. It’s no favour to the rest of creation to deny our superior dignity, for that would also be to deny our unique responsibility. Kateb resoundingly affirms both.

I haven’t tried to summarize Kateb’s argument as a whole. No brief review could do justice to its bold amplitude, its intriguing twists, its problems and provocations. It remains an open question, however, whether any notion of human dignity can survive the corrosiveness endemic to modern thought, which has only grown more radical as that thought has progressed. Kateb promotes a completely secular and non-transcendent notion of our dignity, which, as such, is intended to be immune to such corrosion. The (long) question is whether this project is tantamount to squaring the circle.

Two powerful versions of naturalistic skepticism, that of Darwinian science on the one hand and that of Nietzsche on the other, would subvert any notion of a human difference from other species sufficient to support our special dignity. There’s a double movement of modern thought, which at once privileges human dignity and undercuts it. It’s not clear that Kateb (or anyone else) can adequately refute this radical challenge. It should be clear, however, that I don’t offer this reservation as a reason for avoiding his book.

BY CLIFFORD ORWIN

This review is available online at globeandmail.com.