Focusing on the critical notions of disunity and incoherence so frequently raised in discussions of 'Moby-Dick', the study argues that Melville's 1851 novel depicts two radically different realities governed by principles of continuity and discontinuity respectively, each of which is associated with one of the novel's main protagonists. Based on the assumption that Ahab's world exhibits the same continuities as the cosmos conceptualized by classical physics, this study proposes to regard the captain not as mad, but as a Newtonian subject whose central beliefs about the world are grounded in the same metaphysics as Newtonian physics. In contrast, Ishmael's world is full of inconsistencies, discontinuities, and paradoxes. Beings which populate this heterogeneous multiplicity, in particular the whale which Ishmael attempts to describe and classify, resist all attempts at rendering them continuous. In consequence, they are best described with the concept of complementarity, which originates in quantum physics and denotes a state of affairs characterized by irreducible discontinuity.