If there exist cases where breaking a rule is the best action, then the thesis 'always conform to established rules' implies there are cases where one ought to do what one also ought not to do.
But the fact that these claims are not synonymous does not show that it is false that I ought to do that act which will, in fact, produce the best consequences. The latter claim could be synthetic (or, as Russell would have it, “significant”) but true. Why does Russell think it false? Russell raises the ad hominem objection that Moore’s thesis is flatly inconsistent with the moral conservatism that he goes on to embrace. According to Moore, although “there are cases where [an established moral]