Paradox of Self-Amendment by Peter Suber is repealed, then it possesses what J.M. Finnis called "transtemporal validation". Ross rejects the possibility of transtemporal validation for reasons central to the inference model: it does not work in valid deductive inference, so it cannot work in valid legal change. When in a given inference, a conclusion relies on a certain premise, then if the premise is denied, the conclusion is no longer proved. The conclusion may be inferred anew from other premises, of course, but in any given inference the premises that authorize the conclusion must be affirmed, not denied. So in law, if a rule is repealed, everything it authorized (that is not authorized by something else) must cease to be authorized. So if an act of amendment requires transtemporal validation, then it violates the inference model. But temporal separation in the case of strict self- amendment requires transtemporal validation. If the new AC is authorized by the old AC so that strict self-amendment occurs, and if the old AC is invalidated just as the new AC is validated, then the new AC is either unauthorized or transtemporally authorized. The only alternative under the inference model is for the new AC to be validated by something like Ross's tacit, transcendent rule, which remains in effect as long as we like. But this is to deny that strict self-amendment has occurred (which is part of Ross's strategy). In strict self-amendment the authority for the new AC must be the old AC. So if the new AC is not authorized "from the grave" of the repealed old AC, transtemporally, then it is not authorized at all —for the inference model. In short, temporal separation will not cure strict self-amendment for the inference model. If we accept the distinction between legal and logical contradiction, then temporal separation only prevents a legal contradiction. The logical contradiction survives between the conclusion (new AC) and the premise (old AC) from which it derives its validity. This suffices to invalidate the inference that models self-amendment (when the premises are consistent with one another). On the other hand, if we reject the distinction between legal and logical contradiction, then temporal separation forces us to appeal to transtemporal validation for strict self-amendment. This violates the inference model just as much as contradiction. B. "Valid until amended", temporal indexing, universal self-entrenchment What if the old AC says that it is valid only until amended or repealed? Wouldn't that prevent both legal and logical contradiction between the new and old AC's? The old AC need not assert its exclusive and permanent validity; if it does not, then it is compatible with its replacement in the new AC. This proposal is more complicated than it appears. There are at least four points to make about it. First, it will probably work as advertised, if done with sufficient care. But the inference model requires more than simple care in draftsmanship. It requires a model of deductive inference than can take the proposed nuance into account. So far, temporally indexed deontic logics have only been sketched;[Note 3] they must be fully fleshed out and applied to self-amendment. However, the success of other temporal logics in coping with time-dependent truth values[Note 4] gives me confidence that this project can be fulfilled. Second, the natural way to fulfill it would be to make the old and new AC's logically consistent with each other (by temporal qualification of their claims to validity), while enforcing their temporal separation. Even if this method succeeds in avoiding both legal and logical contradiction, it will require transtemporal validation. Hence, it will satisfy our carefully constructed formal logic without satisfying the inference model. Third, there are new paradoxes attaching to "sunset clauses" that declare time-limits on their own validity. In particular, after they expire, if we want to claim that they are really invalid, the only obvious legal authority to which we might appeal for their invalidity is their own statement of a time-limit on their validity. But they are presumably invalid. If they remain perpetually valid in some dormant, low-level way, sufficient to tell us authoritatively that they are invalid, then at the very least they are self-excepting ontological monsters; at worst, they contradict the time limitations they assert either by becoming wholly invalid or by remaining partially valid. (These paradoxes will be explored further in Section 14.) Fourth, despite first impressions, the logical contradiction between the old and new AC's is not removed simply by rewording the old AC so that it specifically authorizes its replacement or its self-amendment. (More on this in Section 11.) Ross says that the old AC is invalidated or repealed by an inconsistent new AC, adopted under the tacit, transcendent rule. The old AC is repealed by virtue of the legal rule that favors the most recent rule in conflicts between two rules of the same hierarchical level (see Section 16). This rule is often called the lex posterior principle. Ross anticipated the objection that if the old AC incorporated the lex posterior principle, in effect authorizing its own repeal as its successor is established, then the old and new ACs would no longer be inconsistent. This he denies. An AC that incorporated the principle might say,[Note 5] The rules of the constitution are amendable by process P and only by this process, until by this process it is decided otherwise. If such an AC amended itself by changing P for Q, when P and Q were inconsistent in content, then the inference by which the new AC would have come into being would still contradict one premise, the old AC, which would still create an insurmountable invalidity in the inference. Would the incorporation of the lex posterior principle still fail to dissolve the paradox if the old AC said it was to expire at time T (a dimensionless point in time), and if the new AC said it was to take effect at T? The question suggests that some sophisticated logical move is to be made, requiring a different answer from the original situation. But that is illusory. To "incorporate the lex posterior principle" is simply to make it explicit within the new and old ACs that their periods of effectiveness do not overlap, or that the new one repeals the old one to the extent of their irreconcilable inconsistency. Clearly, making this rule explicit in the ACs themselves does not change the fact that they are inconsistent with one another. Moreover, as before, it even presupposes their inconsistency. If one's criterion of inconsistency is the prohibition of what was once permitted, or 75