I don't usually write reviews but because this lacks one, and because as a student of politics and history this has been invaluable help, I'll offer my thoughts.
This is not a polemic like Gray's more recent works; instead it is a series of essays written in the early 1990s which range from issues of toleration and agonistic liberalism to the transition of post communist societies. The broad thesis is that the collapse of the Soviet Union will, instead of heralding victory for liberalism, precipitate a legitimacy crisis and ultimately a return to classic geopolitical conflicts centred around ethnic, religious and resource conflicts. But whilst later books such as 'Black Mass' focus on the practical results of this, Enlightenments Wake is an exploration of the philosophical foundations of the Enlightenment and the implications to classical liberalism and society in general of its collapse.
Though Gray isn't a particularly original thinker, like his mentor Isaiah Berlin, he is extraordinarily well read, has an uncanny feel for the trends of his time, and is an extremely perceptive and critical interpreter of other thinkers. For anyone with any interest in politics he is an invaluable introduction to late liberal thought and often ignored thinkers such as Illich, Oakeshot and McIntyre. In particular the final eponymous essay is, in my opinion, the greatest ever written on the subject of political philosophy.
`The dissolution of morality, as that was conceived in both classical and Christian terms, and the fracturing of the inherited of the inherited Western world-view into a diversity of incommensurable perspectives, which is accomplished in Nietzsche's thought, are irreparable, and any cultural losses they may entail are irretrievable. We shall make the best of the opportunities this cultural mutation affords if we relinquish the search for grounds - metaphysical, transcendental or rational - on which we have run around in nihilism. Instead, abandoning the spirit of seriousness that has animated Western philosophy from its founding we may then come to regard the world -views intimated in our culture lightly and playfully, as evanescent art forms rather than weighty representations of the truth.'