This paper examines developing trust in two related senses: (1) rationally overcoming distrust, and (2) developing a mature capacity for trusting/distrusting. In focussing exclusively on the first problem, traditional philosophical discussions fail to address how an evidence-based paradigm of rationality is easily co-opted by (immature) agents in support of irrational distrust (or trust) – a manifestation of the second problem. Well-regulated trust requires developing a capacity to tolerate the uncertainties that chracterise relationships among fully autonomous self-directed agents. Early relationships lack this uncertainty since car-givers take primary responsibility for determining a child’s interests, reducing the scope (if not the intensity) of potential conflict between self and other. Once agents recognize that adulthood demands foregoing the security embedded in such relationships of dependency, they are free to embrace a more appropriate paradigm of rationality for guiding their thought and action in interactions with others.