Intensity and the Missing Virtual

Deleuze's interpretation of Spinozan philosophy is intrinsically related to the concept of intensity. Attributes are defined as intensive qualities, modal essences as intensive quantities or degrees of power; the life of affects corresponds to continuous variations in intensity. This essay will show why Deleuze needs the concept of intensity for his reading of Spinozan philosophy as a philosophy of expressive immanence. It will also discuss the problems that spring from this reading: in what way, if any, are modal essences modified by the intensive variations of affects? How can the Spinozan conception of eternal modal essences be reconciled with the idea of affections of essence? What is the ethical import of the life of existing modes, when modal essences are considered as eternal? While these questions, in particular the last two, confront each commentator on Spinoza and demand a solution in one way or another, the essay will conclude with a question which is posed from an exclusively Deleuzian perspective: why is the concept of the virtual, which takes centre stage in Deleuze's own philosophy of immanence, missing in his account of Spinoza?