The most common objection to Gray's philosophy is: fine, but what do you suggest we do? If progress is a myth, if utopianism is dangerous, if humans are just animals without special destiny, what is left? Does Gray leave us with a kind of elegant nihilism dressed up in philosophical prose?
Gray has several responses to this, and some are more satisfying than others.
First, he points to what he calls the many lives of humans: the sheer variety of ways human beings have organized their lives, found meaning, and achieved what he considers genuine goods, without any reference to the narrative of progress. The Zen Buddhist monk, the Confucian scholar, the Epicurean, the Stoic, the pre-modern craftsperson embedded in a guild tradition: these are not inferior forms of human life waiting to be improved by the Enlightenment. They are complete ways of being human that the progress narrative tends to condescend to and in practice destroy. In The Silence of Animals (2013), Gray writes with genuine appreciation for forms of non-human life and for human lives oriented toward contemplation, acceptance, and the present rather than toward transformation and the future.
Second, Gray thinks that certain political achievements are genuinely valuable precisely because they do not require the progress narrative. The rule of law, habeas corpus, protection from arbitrary state violence, basic material security: these do not require any belief in human perfectibility. They just require the realistic observation that power unchecked tends toward abuse, and that certain institutional constraints on power produce better outcomes than their absence. This is what he sometimes calls modus vivendi liberalism: a political philosophy that aims at peaceful coexistence among genuinely different ways of life rather than at the triumph of any one conception of the good.
Third, and perhaps most interestingly, Gray has written with increasing attention to non-Western philosophical traditions as sources of genuine alternatives to the progress narrative. His engagement with Taoism, in particular, is not superficial. The Taoist idea that the proper relationship to the world is one of acceptance and responsive action rather than control and transformation resonates throughout his later work.
The criticisms of Gray that need to be taken seriously come from several directions. Steven Pinker, in The Better Angels of Our Nature (2011), argues with extensive empirical data that Gray is simply wrong: violence has decreased, life expectancy has increased, extreme poverty has declined, and these improvements are not trivial or temporary but reflect genuine, measurable, cumulative progress. Gray's response is that Pinker's data selection is tendentious and his theory of history naive, but the empirical argument cannot be simply ignored.
More philosophically, there is a tension in Gray's position. He clearly does not believe that all political arrangements are equally acceptable: he consistently defends liberal pluralism as better than totalitarianism or theocracy. But if progress is a myth and human nature is fixed, what is the philosophical basis for this preference? If humans are just animals, why does it matter whether they live under tyranny or liberty? Gray needs a normative foundation for his political preferences, and it is not clear that his anti-progressivist philosophical anthropology can provide one.