This essay offers a reflection on Professor Joel Alicea's 2024 Harvard Law School Vaughan Lecture - "The Natural Law Moment in Constitutional Theory". My reflection builds on Professor Alicea’s insights by probing the following question: what can scholars of this current natural law moment learn from past moments? 

For: the current transatlantic revival of interest in the classical natural law tradition is merely one amongst several that have taken place within the last century. But the fact we are speaking of a current moment means that these past moments eventually faltered or fell away, leaving the classical natural law tradition’s influence on public law thinking subdued. What sparked these previous revivals? What achievements did they enjoy? Why did they fall away? What does their ultimate fate say about the prospects of the current moment? 

These are big questions, and so here I will only try to venture some very tentative thoughts by engaging with two past natural law moments from the mid-twentieth century, in the United States and Ireland respectively.