I'm curious about the opening line: It is a general and primary principle of rationality, that we should not ... enforce upon our fellows a law which there is insufficient justification to enforce.

On my ordinary understanding of the sentence, it seems to imply that acting justly is necessarily part of what Eliezer means by "acting rationally". Is this right?

More explicitly: the implication is that refraining from "enforcing insufficiently justified laws" is a "general and primary" principle of rationality. Perhaps what is meant is some tautology deriving from (Eliezer's) meanings of "fellows", "justification", and "should". Or perhaps it's just a rhetorical flourish?