To act is to be the author of an intentional bodily movement. I will show that, in order for that authorship to be assured, the agent must both amount to more than the mereological sum of her mental or neural states and events, and have an irreducible causal power over, at least, some of them. Hence, agent-causalism is the best position for any realist about action to assume. I will contend that, contrary to what many have claimed, agent-causalism is not an unscientific theory, since it can ground its view of the agent on a form of emergent dualism that can account for robust forms of agency without having to challenge the natural supervenience of the mental on the physical. I claim that the conditions of possibility for a causally effective emergent self are the presence of neuronal indeterminism and the break of causal closure, both of which will be shown to be compatible with our current scientific picture of the world
