Seneca’s Letters sketch a theory of attentive action according to which distraction is caused by inconsistent beliefs about values, such that the degree of an agent’s attention to an endorsed action is proportionate to the consistency of her beliefs about value, i. e. her proximity to virtue. The agent’s activity of attentive action is co-ordinated with a state of alertness to her interests, which accordingly triggers switches in attention that sustain the endorsed action in single-minded agents or cause distraction if (...) the new interest is irrelevant to it. Seneca’s theory reflects the older Stoic conception of the tensional mental strength of the virtuous agent, which Chrysippus identified as the causal factor over and above virtue that ensures her successful performance of right action. (shrink)