In this paper, I discuss a problem for Kant's strategy of appealing to the agent qua noumenon to undermine the significance of determinism in his theory of free will. I then propose a solution. The problem is as follows: given determinism, how can some agent qua noumenon be 'the cause of the causality' of the appearances of that agent qua phenomenon without being the cause of the entire empirical causal series? This problem has been identified in the literature (Ralph Walker provides what is perhaps the most dramatic presentation of it). But it has never received an adequate solution. In this paper, I argue that Walker’s objection is only decisive if we must understand our responsibility as responsibility for events, but not causal laws. I argue that we need not interpret Kant's theory in this way. I demonstrate that each agent qua noumenon could be responsible for "limited instantiation scope" causal laws which necessitate only the phenomenal actions of that same agent qua phenomenon. Part of this project involves showing that there are relevant constituents of actions which are "rare" enough to instantiate such laws. I demonstrate that, on Kant's view, events in agents’ bodies are not rare enough, but events in agents’ phenomenal souls are.