This paper is concerned with the connection between the causal exclusion argument and the supervenience argument and, in particular, with two exclusion principles that figure prominently in these arguments. Our aim is, first, to reconstruct the dialectics of the two arguments by formalizing them and by relating them to an anti-physicalist argument by Scott Sturgeon. In a second step, we assess the conclusiveness of the two arguments. We demonstrate that the conclusion of both the causal exclusion argument and the supervenience argument (a negation of the so called 'non-identity premise') is not tantamount to the claim that all mental events are identical to physical events and that a cause-supervenience exclusion principle is actually required for the validity of the first stage of the supervenience argument. Moreover, we show that this new exclusion principle makes an epiphenomenalism with respect to mental events an impossible position, and that there are good reasons to believe in its falsity, rendering the supervenience argument inconclusive.