Defending Particularism from Supervenience/Resultance Attack

I take the debate between the particularists and the principlists to be centered on the issue of whether there are true moral principles. One argument the principlists often appeal to in support of their claim that there are true moral principles is the argument from supervenience. Roughly, the argument is made up of the following three statements: (P1) If the thesis of moral supervenience holds, then there are true moral principles. (P2) The thesis of moral supervenience holds. (C) There are true moral principles, and hence particularism is false. In this paper, I argue that the above argument is not sound by attacking (P1). I hold that no general supervenient/resultance base has a robust enough configuration of contextual features as to ground the existence of true moral principles. If I am right about this, I think it would be indicative of a reason to be less confident about the truth of principlism and more confident about the truth of particularism.