The Scalar Stack: Free Will as the Capacity to Direct Causal Flow

Abstract For centuries, the free will debate has been paralyzed by a false binary: either human agents possess metaphysical “uncaused causation” or we are deterministic automata. I argue that free will is not a binary property but a scalar capacity inherent to life itself—the capacity to redirect causal flow toward persistence. This capacity, which I term Hormē (Ὁρμή), is the constitutive drive of living systems and scales through evolutionary complexity: from bacterial taxis to hu- man deliberation. By reframing free will as what life does—not what minds have—I dissolve the traditional stalemate and provide an empirically grounded, testable account of freedom across the tree of life. The framework yields a graduated spectrum of agency—from vegetative (plants) to reflective (human)—each with measurable degrees of causal influence. This approach naturalizes free will without reducing it, offering a unified account that respects both the laws of physics and the lived reality of choice. The result is not just a philosophical solution but a scientifically testable framework with implications for neuroscience, artificial intelligence, mental health, and ethics. Keywords: free will, scalar agency, Hormē, causal flow, degrees of freedom, life‐agency continu- ity, thermodynamics, navigation