 Alternatively, it has been proposed that the Epicureans’ concern is with our control over character development, which Epicurus discusses in On Nature book 25, not free will (Furley 1967; Bobzien 2000). If determinism were true, how we develop would be necessitated—our current character would be the inevitable result of eternal chains of cause and effect, and traceable entirely to external factors of environment and heredity beyond our control. Lucretius is referring to this threat when he talks about the “internal necessity” that the swerve saves us from by breaking the chains of cause and effect. Once again, however, Lucretius’ concern when he describes the swerve does not seem to be the ability of humans to shape their own character development, or the way determinism may threaten it. And leaving that worry aside, having the process of character development caused in part by random atomic swerves seems no better than having it caused entirely by deterministic atomic motions, as far as our control over it. What is needed is not to falsify determinism, but to preserve our ability to use our reason to change ourselves.