In Genealogy of Nihilism, Cunningham interrogates a plethora of thinkers--ranging from Plotinus to Badiou!--and their variegated involvements with a logic of nihilism. At the core of the book, is the claim that throughout the course of the history of philosophy, the logic of nihilism has posits a concept of the nothing, as something. This is to say, that philosophies of the nothing, on account of their attempt to render the nothing as something, betray their own proximity to theologies of creation ex nihilo. Moreover, the key continental philosophies of nihilism, e.g. Fichte, Kant, Hegel, Heidegger, Derrida, operate according to a dualistic logic that is ultimately grounded in a monism that generates their movement and generation. As Cunningham writes, "The aforementioned quandary [aporetic dualisms of finitude] can be seened throughout the history of philosophy. We pay witness to it in the dualisms employed to cope with this aporia. For example: Lacan and Deleuze ground sense in non-sense; Derrida grounds the Text in the Nothing, which is said to reside outside it; Heidegger grounds Being in das Nicht; Hegel, finitude in the infinite, Fichte, I in Non-I; Schopenhauer, representation in will; Kant, phenomenal in noumenal; Spinoza, Nature in God, and God in Nature."
As Cunningham proceeds with an impressive survey of medieval thought, detailing the Pagan aspects of Plotinus' emanation and moving through accomplished discussions of medieval nominalism in thinkers like Avicenna, Ghent, Scotus, and Ockham, we are treated with an impressive demonstration of nominalism's tendency to render the nothing as something.
However, Cunningham's treatment of early modern thinkers like Spinoza, as well as of 20th century continentalists like Heidegger and Derrida are just rife with confusion. Regarding Spinoza's dual-aspect monism, Cunningham writes that in terms of the aproria [of dualisms of finitude], Spinoza "copes with it by generating the dualism God or Nature; God supplements Nature, while Nature supplements God. But the simultaneous movement between each betrays a monism, in terms of a single substance" (59). I can find no way to think of Spinoza's dualism of God and Nature in terms of a "supplement." Indeed, there is only the single substance, namely God, which is identical to nature. But neither concepts function in terms of a supplement--these distinctions are merely aspectival, not substantive. His analysis therefore suffers as he proceeds to relate Spinoza's monism to what he coins "Pan(A)Theistic Acosmim", a rather dubious term that incorrectly attributes transcendence to nature.
The section on Heidegger is interesting for its discussion on the relation of Celan's poetry to Heidegger, but the analysis still suffers from some flat-footed readings of Heidegger's work. Cunningham's basic reading is predicated on a fundamental mis-identification between Being and the Nothing. Heidegger makes no such identification. As Cunningham writes, "Dasein, in understanding death, can comprehend its own nothingness, and so begin to approach Being in an ontological manner, which means precisely, for Heidegger, to approach Being as nothing. (138) Ontology does not denote understanding Being on the basis of nothing--not in Being and Time, and not in any of the later work. Being as event is the event of co-propriation and the nothing is, if anything, the groundless ground of Being. It is important to follow Heidegger's strange machinery as his ontology captures the ways in which nothingness permeates the beings of the world, and the way in which Dasein's thrown projection discloses its ownmost possibility of no longer being possible.
It is for these reasons Cunningham's excursus into the regions of continental thought is plagued with misinformation. Despite such lapses, his study is valuable indeed for its ambition, its accomplished treatments of nominalism in medieval thought, its fine analysis of Hegel, and its provocative Trinitarian thesis.