If Nietzschean necessity is ‘the necessity of chance’, allied to a superiorsufficient reason and key to the concept of Chaosmos, I hope to have shown that certain caveats apply in the course of establishing a common rubric between our metaphysics (so far) and the evolving history of thermodynamics. Over the rest of this book, I would like to demonstrate (pace Deleuze) the various ways in which the Leibnizian strand of Deleuze’s metaphysics serves more productively to illuminate questions of order and disorder shared with scientific discourse. There are certain indispensable elements required of this Leibnizian reading: the primacy of divergence; disparity as the precondition of any event whatever; radical chance; a demonstrable relation to thermodynamics and the second law. The reading itself depends on a construal of Leibniz’s principle of sufficient reason as a principle of dissymmetry, rather than one of symmetry. Its keystone is the novel form of a certain Leibnizian necessity, which governs the selection of events. The necessity in question is the necessary inclusion of all predicates pertaining to an individual in the complete concept of that individual.

Dan Smith systematically and insightfully explores the nuances of Leibniz’s metaphysical logic and its relation to Deleuze’s own in his essay ‘Logic and Existence: Deleuze on the Conditions of the Real’. Of particular interest here is his demonstration that Leibniz’s turn away from Aristotelian formal subject-predicate logic transforms the territory from abstract categorial reasoning to a logic of the event. He focuses on the formulation by Leibniz of the principle of sufficient reason as a reciprocal tenet to the principle of identity, often encapsulated in the shorthand example ‘A = A’. In its most common sense form, this principle states that a thing is what it is – a tautology that represents a necessary truth. A more developed form of the principle is that whenever a given predicate is applied to a given subject, the resulting