Deviant Formal Causation*

N ARM GOES UP; IT IS A SIGNAL that the assassination is to go forward. The physical process that transpired could equally have been a stretching, a voting, or a taxi-hailing, but this particular pro-cess was in fact a signaling. The context in which the arm-rising took place was surely relevant to determining which action it was, for no amount of flailing can constitute a taxi-hailing on a deserted island, or a voting in a monarchy. But let us somewhat improbably suppose that our arm is in a con-text where its rising could have constituted any of these things. The question is why it was in fact a signaling. And as the physical properties of the arm and its setting do not tell us, the natural place to seek an answer is in the arm-wielding agent’s thought. In some way, the agent’s own understanding of the event of the arm-rising contributes to determining the further descriptions under which that event constitutes the intentional action that it is. How is this relation between thought and action to be understood? The broader aim of this paper is to highlight a particular constraint that any theo