This paper is about Ramsey's Principle, according to which a belief's truth-conditions are those that guarantee the success of an action based on that belief whatever the underlying motivating desires. Some philosophers have argued that the Principle should be rejected because it leads to the apparently implausible consequence that any failure of action is the result of some false belief on the agent's part. There is a gap between action and success that cannot be bridged by the agent's cognitive state. At best, the Principle should be relativized to circumstances. We show on the contrary that when the Principle is properly understood, it does not amount to “overburdening” belief. We exploit an analogy between knowledge and action in order to show that intentional action is a source of knowledge relative to a set of beliefs whose collective truth guarantees the success of the action. It does not follow that the agent is explicitly representing all possible obstacles to her action. Most of the relevant beliefs are implicit, in the sense that if they were to be formed, they would be directly or indirectly justified by the agent's experience of acting.