ABSTRACT This essay examines error and both external freedom and internal freedom. There is no external freedom (the latitude to choose) without internal freedom (the capacity to choose). Concerning external freedom, it suggests that errors serve as a derivative basis for natural rights. Concerning internal freedom, it overviews four groundbreaking papers from the 1990s by Stephen Boydstun, who suggested that there is no external freedom without internal indeterminism—specifically that associated with quantum probabilities related to neuronal control processes. Also reviewed is (...) work by Elio Conte and by Andrei Khrennikov. Experiments involving a quantum-like model of cognition are discussed. (shrink)