 For one to be a practical authority over another is, at least, for one to have some sort of control over others’ reasons for action. Whatever else practical authority is, it is the ability to make a difference with respect to someone’s reasons to act. The control involved in practical authority is, however, of a specific sort: it is constitutive control. When a party is an authority over another, his or her dictates constitute, at least in part, reasons for action for that other. (One piece of evidence for this is that when we take A to be an authority over us, we will cite ‘A told us to’ as a reason for action.) But if God’s commands to φ have merely causal power to bring about obligations to φ, then the resultant state of affairs that is the reason for action is its being obligatory to φ—a state of affairs that need not be in any way constituted by God’s issuing any commands. No version of theological voluntarism that is built simply around God’s causal role in actualizing moral obligations implies that God is a practical authority. (See Murphy 2002, 4.3.)