 In On Nature 25, Epicurus says that how we develop depends on us, and not on the nature of our atoms. Based on this assertion and some other passages in On Nature 25, David Sedley (1983, 1988) argues that Epicurus believes that how we act is not determined by the atoms that make up our minds. Instead, from complex atomic systems like the atoms that makes up our minds, there emerges human reason, our desires, and other psychological entities, which cannot be identified with atomic states. All together, these entities make up the person, or the self. According to Sedley, Epicurus thinks that the self acquires causal powers that transcend the laws that bind atomic motion and that can even “reach down” and cause changes to the atoms that make up my mind, and thereby initiate actions. However, the self would not be able to exercise this power if physical laws were sufficient on their own to determine all atomic motions. As a minimal indeterminacy at the atomic level, the swerve allows the self “elbow room” where it can exercise its power to act one way or the other within the laws of physics, but in a way that is not determined by the laws of physics.