The relationship between identity and change, being and becoming, is one of the oldest problems in Western philosophy. Is it possible to bridge the gap between these apparent opposites in order to make sense of a world that seems orderly yet subject to fundamental alterations? Atomistic materialism has attempted to solve this problem by restricting change to the spatiotemporal movement and causal relations of the basic forces and forms of matter, which, including the complications specified in quantum mechanics, have a static set of properties and are governed by unchanging laws. If this approach is too conservative because it ignores the historical transformation of the basic components of every theory, to what extent can we describe such unique and unexpected shifts without ending up with the haphazard chaos of a Cratylan flux? We are apparently caught in the dilemma of saying too much about the process of change and eliminating the possibility of transformation or saying too little and stripping the world of order and continuity. The latter problem confronts intuitionistic theories of singularity, which maintain that unique and unforeseeable events are incommensurable with preceding events and are only accessible through nondiscursive intuition. To a great extent, the prominence of the concept of repetition in continental philosophy is motivated by the attempt to avoid both of these extremes: If singularities arise from a repetition of past events that transforms these events rather than identically reproducing them, then singularities remain continuous with the past but are irreducible to it. In what follows, we will examine the role of continuity and transformation in Deleuze and Heidegger's conceptions of repetition, who, I believe, are the most articulate representatives of two distinct strains of continental thought on this issue. We will conclude with a critical examination of their views. The Serial Method For both Deleuze and Heidegger, repetition is closely tied to the question or problem, a lacuna that continually disrupts the self-evident order of the world. Unlike Heidegger, however, Deleuze maintains that we are not confronted by a single, overarching question but by a changing plurality of problems that are closely connected with everyday activities and concerns. We resolve the indeterminacies in our actual, conscious experience by articulating the virtual order of ideas that underlies experience, though these lacunae are replaced by new ones. According to Deleuze, virtual ideas are completely determinate and, like Kant's regulative ideas, provide the ideal of systematic unity that holds our actual experience together (DR 218-20/168-69).1 In contrast, however, the virtual ideas are not merely regulative but are as real as actual entities and causally determine the latter. According to Deleuze, the idea is a multiplicity that consists in virtual elements, the differential relations between these elements, and the singularities or distinctive points that are generated by these relations (DR 356/278). The elements are holistic and merely formal insofar as they are defined in terms of their relations and have no independent existence. For example, the idea of color consists in the relation of the three primary colors, considered as ideal elements rather than the colors we experience. These relations generate all of the possible colors. Virtual ideas in all their various forms-e.g., mathematical, physical, chemical, biological, social, and linguistic-are reducible to the relation between a set of differential elements; thisindicates one sense in which they are completely determinate (DR 236-37, 266-67, 356,242/182-83,206,278,187; QRS 250-51/ 179). According to Deleuze, virtual ideas are actualized through the progressive determination of the relations between their elements, which results in a continuous emission of ordinary or distinctive points. There are distinctive points, or singularities, in every event that determine the remaining ordinary points, such as the corners of a square. …