A Few Comments on “Revisiting the Doctrine of Intertemporal Law”

I recently read Steven Wheatley’s latest paper, “Revisiting the Doctrine of Intertemporal Law” and found it incredibly interesting. As someone who shares Prof. Wheatley’s interest in the intersection between law and history, I found his effort to systematise the concept into a practical method extremely welcomed and insightful. At the same time, his equation-like approach to “the law in the past”, while incisive, also compelled me to write this post. Here, I will offer a few comments on what I perceive to be the thesis’ limitations, hoping both that Prof. Wheatley will find them useful going forward, and that I can foster some further debate on the subject.

Firstly, let me briefly summarise the paper’s main argument. Prof. Wheatley starts by noting that the doctrine of intertemporal law is apparently paradoxical. On the one hand, the famous original formulation, tells us to appreciate a juridical fact “in the light of the law contemporary with it”, not the law in force today. On the other, we are also asked to examine these facts in terms of their “continued manifestation”, following the “conditions required by the evolution of the law”. The problem arises in determining when exactly does this evolution happen, considering the predicament of hindsight. As Prof. Wheatley explains it:

“We see the importance of the time we examine the available evidence of state practice and opinio juris in relation to the UK’s claim to its continental shelf, made in 1964. The 1963 edition of Brierly’s Law of Nations, written by Sir Humphrey Waldock, observes that the law in this area ‘has undergone a radical change … set in motion by President Truman’s Proclamation’, but the textbook does not confirm the existence of a customary rule. Waldock must conclude, therefore, that the UK’s claim is invalid, and this was the position of most international lawyers at the time. Yet, the 2019 edition of Brownlie’s Principles of Public International Law, written by James Crawford, argues that article 2 of the 1958 Geneva Convention on the Continental Shelf, which recognised the exclusive rights of the coastal state, reflected customary law at the time of its adoption. For Crawford, then, the UK’s claim must be valid at that time. But now we have to explain how we can have two different answers as to the law applicable in 1964”.

In other words, hindsight allows us to know whether a particular practice will eventually become law or not – a privilege contemporaneous observers do not have, and that leads them to argue in defence of the status quo, not progressive development.

Prof. Wheatley offers a method to solve this apparent contradiction through the philosophy of John McTaggart, and his “A-Series” and “B-Series” conceptions of time. In the “B-Series”, events are static and “in a permanently fixed relationship with other events, being ‘Earlier than some, and Later than some’”. In the “A-Series”, events are dynamic “as moving through time, ‘from the far past through the near past to the present, and then from the present to the near future and the far future’”. Prof. Wheatley proposes an “A-Series” approach to customary law:

“[W]ith the benefit of hindsight, we can identify the following distinct periods of time when there has been a change in customary international law: (1) the period when there is agreement that the old customary norm is to be applied; (2a) the period when the new rule was crystallising, but had not yet crystallised, when the old rule must still be applied; (2b) the period after the moment of crystallisation, but before the agreement on the existence of a new general practice accepted as law, when the new rule must now be applied; and (3) the period when there is consensus that the new rule is to be applied. The point is significant because, during the period of transition, the ICJ must apply the old rule to any act occurring in the period of transition, including the period after the crystallisation of the new rule, but before its general acceptance (ie during period 2b). But after there is consensus that a new rule has crystallised, the ICJ must apply the new rule to any act occurring after the moment of crystallisation, including in the same period (2b)”.

According to this conception of customary law, therefore, the proverbial question “what was the (customary) law applicable in any given day” depends on when – at what time – we are answering the question. Past and present-day legal actors may simply never agree. The scholars looking at the event at that time, will find it illegal. Scholars looking at the event today will find it legal.

As I mentioned in the introduction, Prof. Wheatley’s point is well taken. That present and past legal actors might not agree should not be seen as paradoxical, but rather, quite normal. I would, however, offer some additional information to consider, and perhaps arrive at a similar, yet broader, conclusion, through different means.

When discussing the British position in the Chagos Islands case, Prof. Wheatley points out that the UK’s B-Series position rests in the conviction that the International Court of Justice “should decide the case in the same way it would have done in the late 1960s, a time when the legal status of the self-determination norm divided states”. For him, this is incorrect due to the inherent limitations with B-Series thinking. International law is not a “brute fact” static in time, but rather a social construction that moves through time. It is perfectly possible, he says, to agree with the ICJ’s A-Series thinking: even if 1960s lawyers would say self-determination was not legal in the 1960s, 2019 lawyers can say that it was, because they would be able to see that the rule had already crystalised, albeit without consensus – what he calls “period 2(b)”.

Firstly, let me say I agree with Prof. Wheatley’s appreciation of B-Series thinking. International law, like any law, is indeterminate. The meaning of its various provisions can accommodate more than one right answer at any single time. Arguing that the ICJ should decide cases “as it would have” in a specific year is a statement that makes little sense in an indeterminate field like law. The “1960s answer” to the intertemporal problem of self-determination is not fixed. It is, instead, contingent. There is no “one correct (1960s) answer”; there are several. “Correct law” is a spectrum. The British position in the Chagos case simply confuses the majority 1960s opinion with all possible correct 1960s opinions. Dame Rosalyn Higgins was after all not wrong when she defended the existence of a right to self-determination in 1963. Neither is Judge Cançado Trindade every time he writes a sole dissent at the ICJ. The measure of what counts as a valid 1960s interpretation of the law cannot be whether it subscribes to majority view. There is no one single “correct” 1960s answer.  

Secondly, though, Prof. Wheatley’s A-Series alternative also suffers from “correct answer” bias. According to him, we must “think in terms of custom evolving from the future, through the present and on to the past”. But “the law” is not a monolithic concept that “moves” or “evolves” through time. Again, it is indeterminate and contingent. Speaking of “the evolution of the law” implies that there is such a thing as “the (one) (true) law” that moves through time in a sort of genealogy, where each past legal conclusion, each past legal interpretation and theory, is a steppingstone for the next. In this conception, any legal claim that branches out of the one true thread of the history of international law is not law – they are the extinct Neanderthals of international law’s evolutionary process. And we will only know if they become law on hindsight, looking back to see where the one true law ended up travelling through time.

This makes the process of understanding past law basically one of mere discovery. We already have the answer. We are only looking to see how we got to where we are now. But past law is not simply an incomplete version of current law. Past legal scholars and judges did not simply lack some sort of wisdom that we now possess that allows us to examine the law better than our past counterparts.  

In my opinion, this is not how “the law” works, particularly (or, at least in ) international law, because “the law” is not a monolithic concept. There is no “one true law”, either static in time or moving through it. “The law”, in many ways, is a discourse where various actors agree and disagree, contradict and complement each other. It is a set of ideas that rests in the heads and works of countless legal actors, where one does not lead to the other and where “evolution” is a word that should be taken with extreme care. Instead of focusing on whether we are in period 2(a) or 2(b), therefore, it is more important to understand the legal discourse of the time, to see if the specific topic is one of the accepted interpretations of the law back then or not.

This will, of course, be a much more intuitive process when dealing with a 60-year period like in the case of self-determination or the law of the sea (where Prof. Wheatley’s approach could perhaps be the most useful), but it will be a much more complicated affair in controversies separated by centuries or across cultures. Moments 2(a) or 2(b) will be useless in a 17^th century discussion, before the rise of positivism and the modern theory of sources.

Take, for example, the case of settler colonialism. If we follow an evolutionary line of thinking from now to then, we should conclude that odious concepts like terra nullius and abusive treaties of protection were simple a steppingstone to a “better” “post-colonial” international law. This is, of course, not the case. Not just because international law still suffers from the wounds of colonialism, but because this would imply that colonial institutions would have been “proper to their time” “back then”. They had just not evolved yet into a more modern international law – which robs agency to the many contemporaneous thinkers that protested colonialism since the time of Columbus.     

This is similar to the challenges our societies have been dealing with in the context of the Black Lives Matter movement. We are frequently asked to judge historical figures “by the standards of their time”. As Prof. Marlene Daut recently pointed out, these standards are not monolithic. Was it truly impossible to argue against slavery with 18^th century moral standards? Of course not. Early abolitionists were not wrong nor were they “ahead of their time”. They were simply “the minority”, fighting against a social structure that protected itself against change. What hindsight gives us, therefore, is not better legal knowledge, but simply the ability to apply the same law free from the social, moral and political concerns of the time. The worldview of the early 21^st century is not the same as that of the 1960s or the 1530s, even it still is a deeply problematic one.  

In sum, past judges and scholars did not come to the conclusions they arrived at because they were the only available correct option under international law at that time or because that was the specific evolutionary stage at which international law found itself. Many did so because they were concerned with the consequences that such conclusions would have for the international legal order they knew and valued. And this is something that continues to apply to our days. Going back to the example of Judge Cançado Trindade, and as Tara Van Ho recently predicted, “when all is said and done, in 20-30 years, Trindade will be one of two, if not the, most influential judge on the current bench”. This is not because his ideas will become correct in two decades and are mistaken today. It is simply because they have the potential to become majoritarian and we expect future scholars will not be as zealous of the 2021 world order as 2021 judges and scholars.

With that said, though, and before this post gets any longer, I will leave things here. Of course, there is still a lot more to explore on this topic of intertemporality and past law. I have certainly not answered all the questions and there is much nuance that a 2000-word post cannot capture. So, I look forward to engaging with readers further in social media. For now, I will simply stress that Prof. Wheatley and I arrive at the same conclusion: it is possible for something to be considered unlawful in 1960, but lawful in 2021. This is not paradoxical nor controversial. But I arrive at this conclusion through different means. I would be curious to know what Prof. Wheatley makes of these thoughts. In any case, I remain very thankful to him for having written such an interesting article.