  Jarrett (1984, 1989), Ballentine and Jarrett (1997) and Shimony (1984) hold that superluminal signaling is incompatible with relativity theory. Accordingly, they conclude that violations of PI are incompatible with relativity theory, whereas violations of OI may be compatible with this theory. Furthermore, Sutherland (1985, 1989) argues that deterministic, relativistic parameter-dependent theories (i.e., relativistic, deterministic theories that violate PI) would plausibly require retro-causal influences, and in certain experimental circumstances this type of influences would give rise to causal paradoxes, i.e., inconsistent closed causal loops (where effects undermine their very causes). And Arntzenius (1994) argues that all relativistic parameter-dependent theories are impossible on pain of causal paradoxes. That is, he argues that in certain experimental circumstances any relativistic, parameter-dependent theory would give rise to closed causal loops in which violations of PI could not obtain.  