In the categories of ‘act’ and ‘being’ we come to what is arguably both the most basic and the most broad of all philosophical polarities. Act and being is a configuration that in modern times has come to expression more easily in continental philosophy than in analytical, and the categories themselves admit of broader application than any of the other dualities discussed thus far. One sees these categories strongly at work in Hegel, for example, and also in Heidegger, although in different ways and for different purposes. But in fact we have also already encountered this most broad and basic of philosophical polarities implicitly several times in this book, inasmuch as the problems with which this formulation is most fundamentally concerned are those arising out of the confrontation between thinking (‘act’) and being. The polar relation between thinking and being represents one of the most fundamental antitheses of Hegel's Logic; and perhaps Hegel served as something of an impetus for Bonhoeffer's development of these categories in his most neglected book, Act and Being, which will serve as a main focus of this chapter.

So then, when stated in these terms, it becomes obvious that in the present study we have already encountered these categories, for example in Derrida's attempt to expose as a ‘ruse’ the ‘final duality’ between thinking and thinker (i.e., act and being), an attempt that ultimately failed.