According to a widespread view, self-control is a top-down cognitive process that downregulates bottom-up processes, where those bottom-up processes, unless downregulated, are detrimental to self-control. In this paper, I argue that thinking of self-control solely in terms of top-down cognitive control is misleading. Instead, self-control has a necessary bottom-up component in conflict detection, realized by the interplay of the ventral attention circuit and the anterior cingulate cortex. This mechanism generalizes across different forms of self-control. I describe a model of the roles of top-down and bottom-up processing in self-control where bottom-up conflict detection allows the emergence of top-down control. On this model, some cases of self-control failure that are standardly thought to indicate impaired top-down control may often instead reflect maladaptive conflict detection. This insight also carries clinical relevance, such as for understanding ADHD. Intriguingly, this makes self-control begin nonvolitionally. Yet, while agents cannot exert synchronic control over whether conflict detection occurs, they can attempt to facilitate it through diachronic self-regulation, such as by shaping their circumstances to better enable adaptive conflict detection.