Sluga's work in analytic philosophy has been influenced substantially by Wittgenstein to whose early and late writings he has devoted a number of studies.
In Heidegger's Crisis he set out to explore the question why philosophers from Plato till the present get so often entangled in dangerous political affairs.
Sluga analyzes Heidegger's political engagement by putting it into the larger context of the development of German philosophy in the Nazi period.
Sluga's book seeks to show that the willingness to involve themselves politically not only Heidegger, but also of Neo-Kantians like Bruno Bauch, Neo-Fichteans like Max Wundt, and Nietzscheans like Alfred Baeumler was ultimately due to their misconceived belief that they were living through a moment of world-historical crisis in which they were particularly called upon to intervene.
Sluga distinguishes in it between a long tradition of "normative political theorizing" that ranges from Plato and Aristotle through Kant to contemporary writers like John Rawls and a more recent form of "diagnostic practice" that emerged in the 19th century and whose first practitioners were Karl Marx and Friedrich Nietzsche.
Identifying himself with this strand of political philosophizing, Sluga proceeds to examine the thinking of Carl Schmitt, Hannah Arendt, and Michel Foucault as 20th century exemplars of the diagnostic approach.
Sluga agrees with other diagnostic thinkers that the classical institution of the modern state is now giving way to a new form of political order which he calls "the corporāte," whose challenges are defined by the growth of human populations, rapid technological changes, and an ever more pressing environmental crisis.